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    Encyclopedia Arctica 5: Plant Sciences (General)


    Introduction to Arctic Paleobotany and Paleozoic Floras

    Unpaginated      |      Vol_V-0266                                                                                                                  
    EA-Plant Sciences

    (John Walton)





    Introduction 1
    Paleozoic Floras 5
    Downtonian 6
    Lower and Middle Devonian 6
    Upper Devonian 9
    Lower Carboniferous 10
    Upper Carboniferous 10
    Permocarboniferous 11

    Unpaginated      |      Vol_V-0267                                                                                                                  

    Walton: Introduction to Arctic Palsobotany and Paleozoic Floras



            With the manuscript of this article, the author submitted 3 photo–

    graphs for possible use as Illustrations. Because of the high cost

    of reproducing them as halftones in the printed volume, only a small

    proportion of the photographs submitted by contributors to Encyclopedia

    Arctica can be used, at most one or two with each paper; in some cases

    none. The number and selection must be determined later bythe

    publisher and editors of Encyclopedia Arctica . Meantime all photographs

    are being held at The Stefansson Library.

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    EA-Plant Sciences

    (John Walton)






            One of the most interesting geological and botanical problems is

    presented to us by the fossils found by travelers and explorers in the

    Arctic. Collections of fossil plants from places far inside the Arctic

    Circle have been made from 1854 onward, but although they have given us

    valuable information about the geographical distribution of extinct floras,

    they have not, until recently, added greatly to what is known of the

    nature and structure of extinct plants. This is no doubt because these

    regions were little accessible and the difficulties of transport of heavy

    materials from them were great — at least as compared with the relatively

    easy transport problems in temperate and inhabited countries. As a result,

    collections made in the Far North were relativ e ly few in number and contained

    fewer specimens. The great interest, however, of even the early collections

    lies in the fact that they constitute the remains of plants which were very

    different from those found alive in the same regions today. They would

    seem to prove that the climate during the time they were buried and fossil–

    ized was much warmer and more favorable for vigorous growth than the climate

    which prevails in the same spots today.

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            The suggestion, however, has been made that they represent plant

    fragments which were carried by rivers or ocean currents from the south

    and deposited in the North there they are now found, just as the driftwood

    picked up on the seashore may have been derived from distant forests i

    in other lands and climates. This explanation might account for the position

    of some of these plant fossils but is inadequate for the majority of the

    plant deposits; for in many instances there is clear proof that the plants

    which are found as fossils in the Arctic are in or near their original

    positions of growth, and were not drifted fragments. The presence of

    fossil roots in the sedimentary rocks below the remains of branches,

    leaves, and fruits, as well as below the coal seems which are found in

    Spitsbergen, Greenland, and elsewhere in the Arctic gives adequate proof

    that the depots of coal and fossil plants represent the remains of vege–

    tation which grew where they are now found as fossils in the consolidated


            There is no reliable evidence which would indicate that fossil plants

    and coal seems are less frequent in the continental deposits which range

    from the Devonian to the Tertiary in the Arctic than in similar deposits in

    more southern latitudes. In Spitsbergen itself, coal seams are found in

    Devonian, Carboniferous, Jurassic, and Tertiary Strata, north of latitude

    76° N.

            These fossil plants differ markedly from the plants which live today

    in these areas. One may state that, in general, they appear to be the

    remains of plants of greater stature, with larger leaves and stems, than

    the present-day inhabitants; and this suggests the existence of at least

    a temperate climate when conditions for growth were more favorable than today.

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    It is, however, necessary to sound a note of caution. The fossil plants

    of the Paleozoic and early Mesozoic eras, although showing varying degrees

    of relationship to living types, are so distantly related to them that

    it would be unwise to assume that their tolerance of climatic conditions

    was the same as those of their living descendants.

            That the arctic regions are not exceptional in affording evidence of

    striking climatic changes in their history is shown by the fossils found

    in deposits formed during or soon after the Quaternary ice age in Europe.

    In these deposits, typical arctic species of plants are found. In India,

    South Africa, and elsewhere in the Southern Hemisphere [ ?] in the Permocarboni–

    ferous period, there is indisputable evidence of extensive glaciations closely

    associated with a flora in which Glossopteris is the dominant plant fossil.

    In the Northern Hemisphere, in America and Europe, where there is no evidence

    of glaciation in the Carboniferous and Permian, Glossopteris is not found

    in the flora.

            It is important to bear in mind, however, that these arctic fossil

    floras do not differ appreciably from their contemporaries in other parts

    of the world. For example, the Devonian and Carboniferous floras of

    Spitsbergen and Arctic North America and Greenland contain some fossil

    plant species identical with or closely similar to those found in Europe,

    the United States, Canada, and North Africa, and indeed differ only

    slightly from some of the Carboniferous floras of the Southern Hemisphere,

    including Australia. The same applies generally to the floras of other

    geological periods.

            No evidence has been found from fossil plants in the Arctic which

    suggests that in any geological period before the Quaternary any climate

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    EA-PS. Walton: Paleobotany: Introduction and Paleozoic

    climate as cold as that of the present Arctic existed. In fact, the

    evidence suggests that the present cold conditions in the parts of the

    continents inside the Arctic Circle are probably very exceptional.

            It is when we turn to the late Mesozoic and Tertiary periods that

    evidence for warm climates in the arctic is still more convincing, for

    in these periods many of the fossil plants belong to the same angiospermic

    orders and gera and those alive today in temperate and even tropical climates.

            The remarkable difference between the present flora and climate of the

    Arctic and the floras and presumably the climates of pre-Quaternary periods

    has given rise to much controversy. There are four theories which may be

    considered. C. E. P. Brooks in The Evolution of Climate (London, 1922) has

    suggested on meteorological grounds that if the area and depth of the

    Arctic Sea were increased, and its interchange of water with more southern

    oceans also increased, the mean temperature of the Arctic would be raised.

    The effect of ocean currents or distribution of land masses is illustrated

    at the present day by the flora of northern Canada in the Hudson Bay region

    at latitude 60° N., where the soil is permanently frozen at a depth of two

    or three feet from the surface and bears a flora closely similar in compo–

    sition to that of theomore sheltered valleys in Spitsbergen, around latitude

    78° N.

            Although Sir Albert Seward remarked that we cannot assume that plants

    are unalterable over long periods of time in their power of adjustment to

    circumstances he found it difficult to believe that these considerations

    would be sufficient to account for the luxuriance of the Rhaetic flora

    in East Greenland. There would still be a long winter period of darkness

    with presumably very low temperatures, and we do not whether species

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    EA-PS. Walton: Paleobotany: Introduction and Paleozoic

    are capable of adapting themselves to photoperiodic conditions as diverse

    as those which would exist between Greenland and tropical regions.

            The third theory, which is opposed by the majority of geologists,

    is Wegener’s mypothesis of continental drift which supposes that the

    continental masses have been moving about the surface of the globe and

    that some land masses at present near the poles may have been at, or much

    nearer to, the equator in the past. If such changes had taken place, the

    existence of the remains of tropical vegetation in strata now situated

    within the Arctic Circle would be explained.

            The fourth suggestion is that the axis of rotation of the earth has

    changed. It is known of course, that minor cyclical changes in the position

    of the poles occur, but any change large enough to account for the phenomenon

    of the arctic fossil floras is said [ ?] by physicists and astronomers to be

    highly improbable.


    Paleozoic Floras

            Our first information about arctic fossil plants was obtained from

    collections made by the expeditions sent out around the middle of the

    nineteenth century to discover a northwest passage from the Atlantic to

    the Pacific, or to search for a large expedition that had been lost in

    that quest. In 1854, Captain Inglefield brought back fossil wood from

    Atanikerdluk in Greenland, and M’Clintock collected samples of coal fossil

    wood and the core of a fossil conifer from Mercy Bay in Banks Island. A

    few years later, between 1858 and 1864, Nordenskiöld and Blomstrand made

    collections in Spitsbergen, Novaya Zemlya, and Arctic Sibe f r ia. Some of

    the paleobotanical results obtained by investigations of these early

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    EA-PS. Walton: Paleobotany: Introduction and Paleozoic

    collections appear in Oswald Heer’s Flora Fossilis Arctica (1868). For

    further information the reader is advised to consult Sir Albert Seward’s

    work, Plant Life through the Ages (Cambridge, 1931), in which the distri–

    bution over the world of floras of all ages is comprehensively treated.

            As a result of the relative accessibility of Spitsbergen, Bear Island,

    and Greenland from Europe, most of our information about arctic fossil

    floras from high latitudes comes from these parts of the Arctic. Spitsbergen

    provides us with the farthest-north examples of several geological formations

    in which fossil plants have been found.

            Downtonian. The earliest known terrestrial flora in the Arctic is

    that of the Downtonian, and Professor O. A. Høeg ( Norgas Svalbard - og

    Ishavs - Undersøkelser . Skrift 83, 1942) has given a full account of it and

    the Devonian in Spitsbergen. The Downtonian flora from the neighborhood

    of Raudfjorden is a fragmentary one. One good example of the little spherical

    alga Pachytheca and fragments of the large and little-known thalloid plant

    Prototaxites ( Nematophyton ) were found. There were also examples of forking

    vascularized axes of the simple pteridophytes ( Zosterophyllum, Taenocrada (?)

    spitsbergensis , and Hostimella sp.). Floras with similar genera and species

    occur in the upper Silurian of Europe and Australia. There is no doubt that

    the attribution to the Downtonian by Høeg is correct.

            Lower and Middle Devonian . The principal localities in which fossil plants

    have been found in the Lower and Middle Devonian in Spitsbergen are around

    Wijdefjorden and Wood Bay in the northwest, and Dickson Bay and Klaas Billen

    Bay in the central part of West Spitsbergen. A quite considerable flora is

    represented in the collection from these areas and, as Høeg has pointed out,

    “there is not the slightest trace of any influence of a depauperating

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    EA-PS. Walton: Paleobotany: Introduction and Paleozoic

    Arctic climate corresponding to modern conditions.”

            The Psilophytales are one of the principal constituents of the flora.

    These relatively simply constructed pteridophytes are characteristic of

    the Silurian and Lower and Middle Devonian in all parts of the world.

    The plant body in the Psilophytales consists of slender branching stems,

    which are either smooth or have small projections ranging from short,

    stiff prickles to small, leaflike appendages. The sporangia are usually

    terminal on the main branches or on short laterals. The plants were leaf–

    less and rootless; the lower parts of the stems, at least in some instances,

    were rhizomes provided with absorptive hairs and functioning as roots.

            The earliest known land plants are found in the Silurian, and it is

    significant that in the Silurian and Lower and Middle Devonian and we find an

    important proportion of plants in the flora exhibiting this simple or

    primitive type of morphology, which recalls that of the algae in which

    there is no clear differentiation of the shoot into leaves and stem. This

    [ ?] relatively primitive type of construction undoubtedly suggests that,

    during these geological periods, the transition from marine or freshwater

    thalloid plants of algal affinities to the type of plant which d c ould

    exist on land was still in operation.

            The psilophytales as a group are difficult to define and probably

    consist of a plexus of phyla at a similar stage of evolution. Probably

    considerably more than half of the genera found in these Silurian and

    earlier Devonian floras are to be included provisionally in the Psilophytales.

            In the Lower and Middle Devonian of Spitsbergen, we find examples of

    the following genera and species of Psilophytales: Psilophyton spinulosum ,

    P. arcticum , and other Psilophyton spp., Bucheria longa , Hostimella strictissima ,

    and other Hostimella spp.

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    EA-PS. Walton: Paleobotany: Introduction and Paleozoic

            There are also representatives in the upper part of the Middle Devonian

    of lycopod-like plants which are probably the forerunners of the later Upper

    Devonian and Carboniferous arborescent lycopods. Bergeria mimsrensis (Fig. 1)

    bears a considerable resemblance to the large extinct lycopods of the later

    Paleozoic. The This Spitsbergen Bergeria moreover bears a close and

    detailed resemblance to Leptophloeum, a type of lycopod stem which has

    been found in the Devonian of Maine, U.S.A., and Australia.

            Protolepidendropsis pulchra , as its generic name suggests, bears some

    resemblance to the lepidodendroid plants of the Upper Devonian and Carboni–

    ferous. Of the other forms worthy of note, Enigmophyton exhibits flabellate

    leaves with open dichotomous venation bearing some resemblance to an irregu–

    larly divided leaf of the living maidenhair tree, Ginkgo bilboa , but of

    approximately twice the superficial area. Enigmophyton and Platyphyllum ,

    which occur in Spitsbergen, are plants of similar character and in having

    an extended foliar lamina contrast strongly with the Psilophytales and

    other constituents of the flora.

            One of the most interesting of the Spitsbergen plants is a pteridophyte

    called Svalbardia polymorpha . The plant, so far is is known, had slender

    smooth axes up to 46 centimeters long. These branched at an acute angle

    into numerous slender forking laterals; the branching was not dichotomous.

    There was a clear tendency for the ultimate branchlets to be arranged in

    one plane and to be slightly webbed, forming rather ill-defined foliar

    pinnules, the branching systems thus bearing a considerable resemblance to

    a fern frond. On the fertile parts, the small groups of branches bore

    elongated oval sporangia which evidently dehisced by a longitundinal split.

    Svalbardia thus bears some features of resemblance to the better-known Upper

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    EA-PS. Walton: Paleobotany: Introduction and Paleozoic

    Devonian genus Archaeopteris, and indeed its branching system might be

    described as similar to fronds of Archaeopteris but with a more irregular

    and less formal arrangement of the sterile and fertile parts.

            Upper Devonian . Collections were made in Ellesmere Island in Arctic

    Canada by the Second Norwegian Arctic Expedition in the Fram , (L898-1902),

    and the fossil plants were investigated by Nathorst.

            The flora, omitting specimens of uncertain nature, consisted of

    Archaeopteris archetypus and A. fissilis . These are species of a genus

    of fairly large plants which bore large bipinnate fronds, the foliar

    pinnules being either cuneiform or divided into filiform divisions. Sporangia

    were borne in large numbers on fertile pinnae on which the photosynthetic

    lamina was not developed. Some at least of the species of Archaeopteris

    are known to have been [ ?] heterosporous. The sporangium was elongated and

    had no obvious annulus.

            The species found on Ellesmere Island seem to be identical with some

    found by Schmelhausen in the Upper Devonian of the Donets Basin, U.S.S.R.

            Nathorst’s accounts, in 1902, of the Upper Devonian flora of Bear

    Island contain descriptions of some genera and species of previously

    unknown Pteridophyta. Cephalotheca mirabilis had finely divided foliage

    leaflete borne on large fronds. The sporangia were grouped in large pendulous

    bunches which hung on short pedicels at the base of the lateral pinnae.

    Pseudobornia ursine (Fig. 2), assigned to a group of Articulatae named

    Pseudoborniaceae, had whorls of leaves with fimbriate margins borne on

    ridged stems.

            The Upper Devonian age of the flora is suggested by the relative

    abundance of Archaeopteris fimbriata , A. intermedia , and A. roemeriana

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    EA-PS. Walton: Paleobotany: Introduction and Paleozoic

    (Fig. 2-a). The last species closely resembles A. hibernica from the

    Upper Devonian of Ireland. The other genera and species indicate some

    significant affinities with floras of the lower Carboniferous, as for

    example Sphenopteridium sp. and Sphenophyllum subtennerrimum . There are

    also representatives of the arborescent Lycopodiales, Bothrodendron

    kiltorkense , B. wi k g kianum , and other species of Bothrodendron, Lepidodendron,

    and Stigmaria ficoides .

            Lower Carboniferous . Strata of this age containing abundant evidence

    of plant life occur in northern Greenland, Spitsbergen, and Alaska.

    Nathorst, in 1911, described a few fossils from northeast Greenland. These

    include fragments of fernlike fronds resembling those of the Pteridosperm

    Telangium bifidum , Rhodea tenus (Fig. 3-a), a Sphenophyllum , Asterocalamites

    scrobiculatus , an extinct “horsetail” (Equisetales) of very wide geographical

    distribution in the lower Carboniferous, and numerous examples of lycopods

    of the Lepidodendron type. The species found in northeast Greenland are

    consistent with a lower Carboniferous (Mississippian) age for the strata

    in which they were found.

            This flora is of special interest as it is the most northerly Paleozoic

    flora so far recorded, being found between 80° and 81° N. latitude.

            In 1894 and later in 1914 Nathorst described fossil plants from West

    Spitsbergen. He records twenty-six genera including over fifty species,

    a number of which are common and characteristic of the lower Carboniferous

    in continental Europe. Among these may be mentioned several fernlike genera

    and species, probably most of them are pteridosperms (a group of gymnospermous

    plants which probably persisted from the Upper Devonian until well into

    Jurassic times). The most characteristic features of this group were the

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    large fernlike fronds on which seeds were borne in many of the genera.

    The group has sometimes been referred to as the seed ferns. Among those

    described by Nathorst are Adiantites sp. apd Cardiopteridium spetsbergense

    (Fig. 3-b), which are characteristic constituents of the calciferous

    sandstone series of the lower Carboniferous of central Scotland. The

    extinct horsetails are presented by Asterocalmites scrobiculatus .

            The arborescent lycopods are well represented, and from the discovery’

    of tree stumps in positions of growth in the strata, and the existence of

    considerable coal seams, it is evident that extensive and flourishing

    forests existed there is lower Carboniferous times. Nathorst identifies

    examples of Lepidodendron, Lepidophloios , Sigillaria , and Porodendron

    among the remains of these forest trees. Quite a large number of seeds and

    polliniferous fructifications occur, including one names Thysanotesta

    which has a hairy plume attached to the seed body and which Nathorst

    suggested was evidence of a wind-dispersal mechanism.

            From Bear Island, Nathorst described a mainly Upper Devonian flora,

    but there are a few species in it which are found in the lower Carboniferous.

    It would, however, be unjustifiable on the bases of these elements to

    conclude that a lower Carboniferous flora is represented in Bear Island.

            Professor T. G. Halle has recently investigated collections from the

    northern Scoresby Sound area of East Greenland, including some admittedly

    fragmentary remains of Carboniferous plants which can be matched most

    clearly with plants found in the Carboniferous limestone group in the upper

    part of the lower Carboniferous is Scotland as well as with elements of

    the Namurian flora in western Europe.

            Upper Carboniferous. Nordenskiöld in 1875 discovered fossil plants

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    in Novaya Zemlya, in arctic Russia, in shales lying above and conformable

    with limestone containing Productus and Spirifer — indicating that the

    plant-bearing beds were of upper Carboniferous or possibly Permian age.

    The plant remains are long stra-shaped leaves of Cordaites , an extinct

    genus of gymnospermous trees. Recently Halle has identified the character–

    istic upper Carboniferous genera Alethopteris and Neuropteris , which are

    known to be the fronds of pteridosperms, in collections made in the

    Scoresby Sound area of East Greenland. They indicate the presence of a

    Westphalian horizon of the Upper Carboniferous.

            Permocarboniferous. Professor R. Florin has identified the pteridos–

    perm genus Callipteris and a conifer Lebachia , fossils which indicate an

    age not earlier than the upper Carboniferous Stephanian, and possibly the

    Permian, in the northern Scoresby Sound area.


    John Walton

    Mesozoic Paleobotany

    Unpaginated      |      Vol_V-0280                                                                                                                  
    (EA-Plant Sciences. Thomas M. Harris)




    Triassic 2
    Rhaetic and Basl Liassic 2
    Lower Jurassic (Liassic) 5
    Middle Jurassic (Lower Oölite) 6
    Upper Jurassic 6
    Lower Cretaceous (Wealden) 7
    Middle Cretaceous 10
    Upper Cretaceous 10
    Upper Cretaceous Flora of Alaska and Greenland 13
    General Conclusions: Past Climates 16
    Comparison of Floras in Same Period 18
    Bibliography 22

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    EA-Plant Sciences. Harris: Mesozoic Paleobotany



    Fig. 1. Mesozoic floras of the Arctic and Subarctic 2-a
    Fig. 2. Some Mesozoic ginkgoalean foliage of arctic regions 15-a

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    EA-Plant Sciences

    (Thomas M. Harris)



            The arctic regions are as rich in Mesozoic plants as other parts of the

    earth but they figure disproportionately large in the history of paleobotany.

    During the nineteenth century certain Swedes were among the pioneers in sci–

    entific arctic exploration and a young man, A. G. Nathorst, was appointed to

    a new research post in paleobotany at Stockholm, largely to deal with arctic

    fossil plants. Nathorst and those who followed him by no means confined them–

    selves to the Arctic, or indeed to the Mesozoic; but Nathorst’s work on

    Mesozoic plants certainly led the world and inspired workers in many other


            As time passes, these old investigations, though often models of work

    in their day, have become out of date and their significance gradually changes

    from what they actually proved to the suggestions which they afford of future

    possibilities for research. It is, of course, a common characteristic of work

    on material from remote places that it consists of exhaustive investigations

    of material collected at long intervals, and much of it is in need of revision.

    In this article future needs are pointed out.

            The subject matter is here arranged chronologically under the Triassic,

    the Jurassic, and the Cretaceous. Recent geochronology assigns a length of

    some fifteen million years to the Triassic, barely ten million years to the

    Jurassic, and as long as forty million years to the Cretaceous; but our know–

    ledge of the floras is not in this proportion, for the Jurassic are best known

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    EA-PS. Harris: Mesozoic Paleobotany

    (especially if we include transitional beds at the two ends of that period),

    next comes the Cretaceous, and the Triassic is the least known. This is

    equally true of north temperate regions generally and of the Arctic. (see Fig. 1)


    1. Triassic

            The arctic Trias has few plants until its very end. Marine Triassic

    is well known, as is continental Trias of the barren, desert sandstone

    type — but not the deltaic type of rock in which plants occur. The sole

    exception is in East Greenland where, in the early Trias of Hold with Hope

    (just below the Myalina kochi zone), there is a shale with small plant frag–

    ments including a Selaginella cone, Selaginellites Polaris (31), yielding

    surprisingly well-preserved spores. Clearly this region should be searched

    again for richer deposits; any progress in knowledge of the Trias would be

    welcome. Our lack of knowledge of the Middle Trias, is surprising, [ ?] although

    the period is represented by two accessible and excellently preserved floras

    in Austria and in Virginia.

            According to Newton and Teall ( [ ?] 4 3), ill-preserved Triassic plants occur

    in Franz Josef Land; and Nathorst (37) recorded a few supposedly Triassic

    plants from the island of Kotelnyi (New Siberia), but the specimens could

    equally well have been Lower Jurassic. Now Lower Triassic plants have been

    recorded from the Arctic, and there is thus no problem to decide whether a

    flora belongs to the Mesozoic or Paleozoic.


    2. Rhaetic and Basal Liassic

            The last stage of the Triassic is called the Rhaetic. It is included

    in the Trias because its chief ammonites are of Triassic rather than Liassic

    affinities, but from the paleobotanical angle it would be natural to include

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    Fig. 1. Mesozoic floras of the Arctic and Subarctic.

    (the numbers refer to the sections in the next): 1, Triassic; 2, Liasso-Rhaetic;

    3, ? Liassic; [4, Middle Jurassic wanting]; 5, Upper Jurassic; 6, Lower Cretaceous;

    [7, Middle Cretaceous wanting]; 8, Upper Cretaceous.

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    EA-PS. Harris; Mesozoic Floras

    it in the Jurassic. The Rhaetic marks the beginning of submergence of the

    Triassic land by the Liassic sea, and its flora passes continuously into the

    Liassic. This submergence was rather widespread, and a good many Rhaetic

    floras are known or at least attributed to this period. The flora of

    Scoresby Sound, East Greenland, is one of the largest of its period. It

    was first discovered by Scoresby; Hartz (18) wrote a pioneering paper; and

    it has been redescribed by Harris (17) and then more fully by Harris in a

    series of papers (10-14, 16). A northward extension of this flora was more

    recently described by the same author.

            This flora occurs in a river delta which continued to receive deposits

    on its surface through the Rhaetic into lower Liassic ( Angulatus zone) time

    and perhaps rather longer. It is followed by a Liassic marine fauna of

    Jamesoni zone which sets an upper limit to the age of the plant-bearing rocks.

            The plant-bearing series are favorable for study, being geologically very

    simple. Plants occur locally at all levels in the plant-bearing series in

    what seem to be old river channels. There are many thin coal seams and old

    land surfaces with vertical roots.

            Although each plant bed has a flora with some features of its own, there

    is a simple underlying scheme. Every bed of the lower 60 meters of the series

    has a selection from a certain list of species, the “ Lepidopteris flora,” and

    each bed of the top 30 meters has selection from a second list, the “ Thaumatop

    teris flora.” These two floras have a few species which range through both,

    but most are rigidly restricted except through about 5 meters of rock where

    mixture occurs. Thus two plant zones can be clearly made out, and both are

    widely recognizable, for example, in Europe (and even, it has been claimed, in

    Japan). The older Lepidopteris zone is correlated with the European Rhaetic

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    flora, the younger with the European basal Liassic flora. The flora of the

    two zones comprises some 200 named species (although this number includes

    separately named leaves, seeds, and other parts of the same plant, as well

    as many unnamed types of charcoal and [ ?] microspores); it is therefore among

    the largest Mesozoic floras, and nearly everything was well enough preserved

    for its microscopic structure to be investigated.

            The name part of the flora is made up of cryptogams and seed plants.

    The cryptogams include 1 filamentous alga, 4 thalloid hepatics, 6 Equisetales

    (usually the commonest fossils), 15 lycopods, almost all being isolated mega–

    spores, and 22 Filicales (often abundant). The families represented in this

    last order are Osmandaceae, Dipteridaceae, Matoniaceae, Marattiaceae, and


            The seed plants includ 21 presumed cycads, 7 presumed pteridosperms, 8

    Caytoniales, 31 Bennettitales (often abundant), 20 Ginkgoales (often abundant),

    35 conifers, 1 possible dicotyledonous plant, and 25 unclassified reproductive

    organs, mostly no doubt belonging to the members of the above groups. Several

    of these seed plants are of great interest because leaves and reproductive

    organs are associated and there is, moreover, structural evidence for associ–

    ating them. This applies, for instance, to the cycads Nilssonia and Beania ,

    and to the pteridosper-like plants Lepidopteris and Ptilxozamites and their

    reproductive organs.

            The flora was investigated rather differently from other Mesozoic floras,

    in that the larger microfossils were described — particularly leaf cuticles,

    isolated megaspores, and isolated seeds. Many of these are widespread and

    abundant although not found as ordinary fossils, and this was taken to indi–

    cate the existence of an inland flora of different composition from that of

    005      |      Vol_V-0287                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    the Deltaic marshes, and represented only by small water-borne fragments.

            If these microfossils are excluded, the flora becomes astonishingly sim–

    ilar to that of the corresponding one of south Sweden (Scania) where both

    zones are present; nearly all the species are in common, and in the main the

    same species are abundant. It is indeed so similar that it is not possible

    to state with assurance the existence of any general difference. It may,

    however, be true that Ginkgoales, especially Czekanovskia , are rather more

    abundant in Greenland, and that Thinnfeldin , which is rare in Sweden, is even

    rarer in Greenland. This genus is abundant in the floras of the same age in

    southwest Germany.

            The flora at present known represents one whole season’s collecting and

    some material collected previously on brief visits. There are indications

    that further collecting in Scoresby Sound is not likely to [ ?] y ield many new

    species (since most of them were met rep [ ?] eatedly) but it should certainly

    yield much botanical interest. The northward extension of this flora,

    previously mentioned, seems a little different from the representation in

    Scoresby Sound and should repay both floristic and stratigraphic study.


    3. Lower Jurassic (Liassic)

            Unfortunately we have no large standard middle or upper Liassic flora;

    indeed the plants of the whole period are imperfectly known. The only near–

    arctic flora claimed to be of this approximate age is from the Upper Matanuska

    Valley, Alaska (28). It has only ten species, but all were identified, mostly

    with Liassic ones from Bornholm. None of these identifications is supported

    by microscopic evidence, but still a tentative determination of the age as

    Liassic is reasonable, even though an age as old as Rhaetic or as young as

    Lower Colite would not be excluded by the plants concerned.

    006      |      Vol_V-0288                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

            The interest of this flora lies in the research possibilities it suggest.

    Much of the rock is volcanic ash; this suggest petrifactions. There are associ–

    ated marine faunas; this suggests a possibility of accurate stratigraphy. If

    the preservation is good (cuticles are not mentioned), here is a possibility

    of advance in botanical knowledge of a little-known period.


    4. Middle Jurassic (Lower Cölite ).

            Plants of this period are very poorly represented in the Arctic. A few

    plants of this age ( Sagenopteris and some others) occur in Alaska but little

    is yet published about them ( See Martin and Katz (32), Knowlton (28)). The

    marine Jurassic of East Greenland is, however, fairly rich is undescribed

    petrified wood.


    5. Upper Jurassic

            One of the larger floras of Spitsbergen (Cape Boheman) has been regarded

    as Upper (or even as old as Middle) Jurassic, but the majority if not all of

    these floras are now generally included in the lowest Cretaceous, There is

    thus no known and satisfactory arctic Upper Jurassic flora, and indeed this

    is a period of which our knowledge is rather scant. It may be mentioned that

    moderate-sized Upper Jurassic floras occur in northeast Scotland (49; 54),

    though this is outside the limits of the regions here included.

            A great deal of petrified wood is known from the arctic regions — much

    of it originally preserved in marine Jurassic rocks and then removed by glacia–

    tion and thus of rather insecure age, but other material accurately dated.

    Collections of such wood have been described by Gothan from King Charles Land

    and other parts of Spitsbergen (8; 9), its age being largely Upper Jurassic

    or lowest Cretaceous. A few others were described by Walton (56) from Spits–


    007      |      Vol_V-0289                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

            Mesozoic petrified woods have been rather neglected in recent years,

    and [ ?] G othan’s accounts remain among the most complete [ ?] yet written. In them,

    several new types were recognized and others identified with known types.

    There has never been any proof that petrified woods are not excellent and

    well characterized types, as well as of evolutionary interest, and a return

    should certa [ ?] ly be made to the study of this material.

            A small flora from a Spitsbergen boulder in undetermined age may be

    mentioned here. It was described by Selling (45; 46) and includes some

    lycopodinian megaspores and some excellently preserved gymnospermous roots.


    6. Lower Cretaceous (Wealden )

            This period, which in parts of Europe passes gradually down into the

    Upper Jurassic (Purbeckian), was for a time include by some in the Jurassic,

    but most of the considerable confusion which has existed about the correla–

    tion of these floras is due to real doubt about their age and not merely to

    the name of the period to which the Wealden is assigned. One such flora is

    found in northern Siberia at the mouth of the Lena River, another on [ ?] Andö

    in the Lofoten Islands, Norway, and there is also a series of floras from Spits–

    bergen and from Franz Josef Land which it is convenient to take all together.

            The Lena River flora (22), which could equally well be Upper Jurassic,

    shows some quite handsome specimens of Podozamites, Nilssonia, and other well–

    known Mesozoic gymnospermous leaf types. Several ginkgoalean leaves occur. The

    collection gives one the impression that further field work would yield valu–

    able results.

            The flora of Cape Boheman, Spitsbergen, has been regarded as the oldest.

    It was described by Heer (19), and correlated with Middle Jurassic. Heer

    008      |      Vol_V-0290                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    determined some 32 species, about half of which would seem nowadays to be

    justifiably identified. The commonest fossils are ferns, members of the

    Ginkgoales, and (possibly) coniferous leaves placed in the genus Podozamites ,

    which might, however, equally wall belong to the Ginkgoales. Cycad-like

    leaves are remarkably rare or perhaps absent, the only ones mentioned being

    determined on very weak evidence, and there are some curious cones which

    would no doubt have botanical interest if studied.

            Nathorst (42) pointed out that Herr’s identification of certain fossils

    with Middle Jurassic ones was unreliable, and later (38) he stated that they

    are younger than a marine Oxfordian Aucella horizon. Their age could there–

    fore be Upper Jurassic or perhaps Lower Cretaceous. So far as the author

    knows. The preservation of this flora is not good enough to permit microscopic


            There is another flora at Advent Bay, Spitsbergen, described by Nathorst

    (42), which seems younger than the Cape Boheman flora and which certainly

    seems to be of Wealden age. It includes several Ginkgoales and some conifers,

    in particular Elatides curvifolis , whose identity is confirmed by Florin (6).

    This is a characteristic species of the Wealden of Franz Josef Land. This flora

    includes some interesting cones, and, as cuticles are preserved, there is again

    scope for work of botanical interest.

            The Walden floras of Franz Josef Land are of special importance because

    much of the material is petrified. It is indeed one of the only two known

    petrified floras of Mesozoic age; elsewhere, only a few genera such as Cycadeoidea

    are petrified. It has thus a special importance and has been the subject of

    exhaustive investigation. Solus-Laubach (53) gave a useful account, and later

    Florin (5; 6) dealt with the Ginkgoales which make up the bulk of the flora.

    009      |      Vol_V-0291                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    Apart from these, there are only the conifer Elatides curvifolia and a few

    fragments belonging to other groups.

            Among the Ginkgoales there is a remarkable preponderance of species with

    strap-shaped leaves borne on dwarf shoots. Such leaves were formerly called

    Pheonicopsis , but Florin distributes them on cuticle characters (particularly

    stomatal distribution) into several new genera. The leaf vascular bundles of

    these fossils show remarkably close agreement with those of the leaf of Ginkgo

    biloba ; differences exist, however, in the characters of the bundle-sheath

    and of the secratory cavities.

            As this flora is based on collections from five localities, there is some

    reason to suppose that, although it remains far from exhaustively collected,

    our knowledge of it is representative. No flora in the world of any age shows

    such a preponderance of Ginkgoales, either reckoned as the fraction of the

    total number of species in the flora or on relative abundance of specimens.

    One may feel reasonably sure that this fact has some paleogeographical sig–

    nificance, as, in floras of the same age in Europe, Ginkgoales are few but

    conifers predominate.

            A small flora from Cape Staratsch in Ice Fjord, Spitsbergen, was described

    by Heer (22, and some notes in 1873). It includes a few fern fragments, a good

    many conifer shoots and cones, and some Ginkgoales. There are no Bennettitales,

    but there is one specimen referred (unjustifiably) to the monocotyledons. The

    correlation of this flora is quite vague; Heer thought it younger than the

    Wealden flora of Greenland, but this would seem unlikely. The plants are con–

    sistent with a Lower Cretaceous age. Nathorst (42) referred to it as “Upper

    Jurassic,” but by that he apparently meant “Wealden,” which is now placed at

    the bottom of the Cretaceous.

    010      |      Vol_V-0292                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

            A small flora of uppermost Jurassic or Lower Cretaceous age has been

    described from Andő in the Lofoten Islands, Norway, by Johansson (26). The

    material was very limited and the plants unpromising little pieces of leaves;

    but they were investigated microscopically and yielded three species of Sci

    adopitys — more, indeed, than in any other flora. It is not, however, safe

    to assume that the abundance of this remarkable genus of conifers is unique,

    for such fossils in other floras have been either neglected or given a name

    like Pityphyllum , which has been used so widely as to have no botanical mean–



    7. Middle Cretaceous

            No arctic flora can be d e finitely ascribed to this period. This may well

    be because of lack of standard floras in Europe, for some of the Spitsbergen

    floras might belong to it — for example, that described by Heer (22) from

    Cape Staratsch. Heer originally placed his Atane flora of Greenland some–

    where in the middle Cretaceous, but Seward (48) has expressed doubt about the

    correlation and revards it as much younger.


    8. Upper Cretaceous

            This is the period during which the Mesozoic type of flora gave place

    to the modern type, the change being largely the disappearance of the Ben–

    nettitales and some other Mesozoic gymnosperms and their replacement by a

    large number of kinds of dicotyledonous leaves. Other gymnosperms declined

    only gradually.

            The change has been re g arded as sudden, and so it certainly is in rela–

    tion to the relative stability from Upper Trias to middle Cretaceous; but

    its suddenness may be partly illusory. It was, however, slow enough to be

    011      |      Vol_V-0293                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    scarcely perceptible during the long period, perhaps several million years,

    when a great thickness of rock was deposited in Alaska and in West Greenland.

            Heer considered that there were four main stages in the plant-bearing

    series. The oldest is the Kome or Kuk series which he supposed was Lower

    Cretaceous; then came the Atane series in the middle or Upper Cretaceous,

    then the Patoot series of the uppermost Cretaceous, and finally a great Ter–

    tiary flora which he placed in the Miocene. Each series is represented by

    several isolated localities and there is no proof that the rocks ascribed

    to one series form a geological unit.

            Later writers have pushed these together. The Kome series is ascribed

    to the middle part of the Upper Cretaceous, the next two to a younger stage

    of the Upper Cretaceous (but their validity as recognizable stages is doubt–

    ful), and finally the flora regarded by Heer as Miocene is moved into the

    older part of the Eocene.

            The geology was revised by White and Schuchert (57), but since then

    efforts at correlation have been based almost entirely on the plants; and this

    largely depends on the proportion of characteristically Mesozoic gymnosperms

    to the characteristically more recent dicotyledons. Such [ ?] correlation may

    prove very reliable if the chan [ ?] ge in flora was everywhere simultaneous; but

    if, as some have suggested, the Tertiary type of flora arose in the Arctic

    and migrated south very slowly, it would be misleading. The author under–

    stands that work at present in progress (in 1950) on the geology of the West

    Greenland Cretaceous and Eocene (which have several marine horizons) is likely

    to result in considerable clarification. If so, the geologists concerned will

    deserve much gratitude.

            Taking this flora, then, as a whole, we can certainly say that it

    012      |      Vol_V-0294                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    comprises several stages (though our knowledge is not good enough to define

    them) and includes a large number of species, many of which are represented

    by fine large leaves with associated reproductive organs. Preservation is

    very uneven in different localities; many provide only burnt-out casts (the

    fossils most prized by the early investigators and still considered valu–

    able by many modern paleobotanists), but others give excellent cuticles

    and spores, and sometimes the fossils are so little altered that they can

    be swelled with potash and then give good sections. Though much is known,

    the possibilities for future work are very great.

            Since Heer’s time, the flora has been investigated by several others.

    Seward (48; 50) and Seward and Conway (51; 52) contributed a general re–

    vision of Heer’s work, and special aspects are described by Arnold (1),

    Miner (33; 34), Nathorst (37; 39; 40), and Tutin (55). Little further

    reference will be made to Heer’s part in this work because Seward’s revision

    of it was com p rehensive. It may be remarked, however, that even if Heer may

    have been hasty in his description, his works are a monument to his industry

    and boldness. His labors must be considered largely responsible for sev–

    eral later researches on the arctic floras.

            Among the most interesting cryptogams are a series of [ ?] Gleichenia

    like ferns ( Gleichniopsis ), some of which have numerous small sporangia and

    thus approach the Polypodiaceae, though most of them are not yet securely

    classified on sound characters. Equisetales occur but are not common;

    evidently they had by that time become an unimportant element of the marshes.

            Among the interesting gymnosperms, there are several undoubted Ben–

    nettitales (including species of Pseudocycas , Nilssonipotaris , and Ptilophyllum )

    013      |      Vol_V-0295                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    from all of which cuticles have been prepared showing bennettitalean stomata.

    No true cycads occur — apart [ ?] from a leaf assigned to Pseudoctanis , but

    which has not been confirmed by microscopic study. Ginkgoales of several

    genera are common and there is a wealth of conifers. Heer identified sev–

    eral species of Sequoia , which are very abundant, and also of Sciadopitya ,

    a genus now confined to Japan.

            Angiosperms are very numerous, especially in the later stages, though

    these are often recognized as Tertiary. They are represented by very large

    leaves of anything but arctic aspect. Genera determined include Platanus ,

    Aralia , Magnolia , Laurus , and Cinnamomum , though Seward is characteristically

    cautious in his identification. These matters are referred to when this flora

    is compared with the Alaskan flora.


    Upper Cretaceous Flora of Alaska and Greenland

            Hollick (24) brings together what is known of this flora and adds greatly

    to it. He considers there are in reality two floras — one from the Yukon

    River which is correlated with the Dakota sandstone flora and “early” Upper

    Cretaceous, the other from the Alaska Peninsula which is correlated with the

    Montana flora and “late” Upper Cretaceous. Both floras occur in a thick series

    of sediments, and there is hope that further collecting in marine beds may

    lead to their division into further stages and more precise correlation.

            Both floras are large; together they include over 200 named species and

    they both include a similar, rather small proportion of “Mesozoic” gymnosperms.

    The bulk of the species are dicotyledonous trees, represented by leaves, and

    most of these are peculiar, being confined to one locality or even one speci–

    men. This is a clear indication that progress is needed on the botanical side.

    014      |      Vol_V-0296                                                                                                                  
    EA [ ?] PS. Harris: Mesozoic Paleobotany

    Nevertheless the dicotyledons in the two floras seem to have a similarity in

    aspect; an important difference is the abundance of the Platanus -like leaf

    Credneria in the Y [ ?] u kon River flora and its absence in the other. It appears

    also that different gymnosperms occur in the two floras.

            For the following description the two floras will be taken together and

    at the same time compared with the West Greenland flora, which is only

    slightly farther north.

            Cryptogams . In both the Alaskan and Greenland floras, the Equisetales

    are rare or else unknown. Evidently this group had then lost its place as

    the dominant one of swamp vegetation, presumably to reeds and swamp-inhabiting


            Ferns occur in both regions but in strikingly different numbers. In

    Alaska they are very rare, and, although several species are distinguished,

    they are based on a few small pieces. In Greenland, ferns are among the most

    abundant fossils and so most of the species are based on fine specimens. This

    difference seems to suggest that the Greenland flora lived under a somewhat

    different climate, perhaps one with more humid summers. It may be pointed out

    that the specific determination of several of the Alaskan fern fragments and

    their reference to such genera as the Mesozoic Stachypteris or the modern

    Pteris , Asplenium , Phegopteris , or Dryopteris , do not represent the discovery

    of important facts about sori on which these genera are based, as the iden–

    tifications were made from leaves without reference to reproductive organs.

    Such determinations raise grave doubts about the validity of the determinations

    in other groups, especially among the angiosperms. Most paleobotanists would

    have preferred to call these fragments Sphenopteris sp. A , Pecopteris sp. B ,

    and so on.

    015      |      Vol_V-0297                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

            Gymnosperms . Three species of Sagenopteris are distinguished, each from

    a single imperfect leaflet. This must be one of the last records of the Cay–

    toniales; closer study is most desirable.

            Several species of Nilssonia (Cycadales) occur, some of them being

    remarkably abundant and widespread. In view of their absence in West Greenland

    this is rather surprising.

            The Bennettitales on the other hand are rare and indeed doubtfully repre–

    sented in Alaska, though common in Greenland. This is a “ Cycadites sp .” Com–

    parable with a Greenland Pseudocycas and a leaf placed in Pterophyllum which

    might, in the absence of knowledge of its cuticle, belong to that genus or to


            The Ginkgoales are well represented in both floras, and several of the

    species look rather similar (see Fig. 2) . Their names are all different, but the specific

    names of Ginkgoales are quite arbitrary in the absence of information about

    cuticles. The abundance of this group in arctic floras in general is remarkable.

            Conifers are important in both floras, and forms resembling in appearance

    Saquoia sempervirens are frequent. A different array of generic names are used

    by Seward, Hollick and other paleobotanists, but this merely emphasizes the

    need of further knowledge. A strange feature of the Alaskan flora is the genus

    Podozamites (absent from Greenland); further knowledge of the Alaskan material

    of this presumably heterogeneous Mesozoic conifer group would be of value.

            Angiosperms . In both floras there are numerous species of dicotyledons,

    represented by large and abundant leaves. Apart from Platanus , however, their

    naming and treatment are almost entirely different. Seward, as is well known,

    tended to unite a range of specimens into a few species, but Hollick distin–

    guishes a great many, and this partly accounts for the much longer species list

    015a      |      Vol_V-0298                                                                                                                  

    Fig. 2. Some Mesozoic ginkgoalean foliage of arctic regions (original

    specimens are 2-6 inches long): A, Czekanowskia; B, Sphenobaiera; C, Baiera;

    D, Ginkgoiteas obovata; E, leaf bundle of Czekanowskia; F, leaf bundle of one

    of the Phoenicopsis’ group (Stephenophyllum); G, leaf of Ginkgoites taeniata;

    H, leaf of Ginkgo digitata.

    016      |      Vol_V-0299                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    in the Alaskan flora. Inspection of the figures suggests that there is indeed more

    variety in the Alaska flora and that rather more species should exist there.


    General Conclusions: Past Climates

            Everyone who has collected fossil plants in the Arctic must have been

    struck by the difference between the sparse flora growing there today and the

    abundance of the fossils. Of course the subject is only part of the study of

    the past climates of the world, but nowhere, save perhaps in true desert, can

    the contrast be more marked.

            The smaller Mesozoic arctic fossil floras give little basis for judgment

    on climate, but the larger ones, and particularly the largest — the Liasso–

    Rhaetic of East Greenland, the Lower Cretaceous of Spitsbergen, and the Upper

    Cretaceous of West Greenland and Alaska — all indicate the existence of condi–

    tions where large plants could flourish: that is to say, a climate with a

    growing season favorable enough for trees to grow, many of them with large

    leaves. One other significant fact is that all the fossil woods of the Meso–

    zoic, and they range widely, show annual growth rings indicating the existence

    of growing and resting seasons. This indeed is true of Mesozoic fossil woods

    generally. Here, in the author’s opinion, the simple indications end, and

    the more cautious scientists may reasonably conclude that this is all we know

    of arctic Mesozoic climates.

            It is possible to go further if we accept the rich of error through wrong

    assumptions. The Mesozoic flora, in the main, is so unlike that of today

    that we are precluded from using identifications as evidence of past climate.

    If a late Tertiary northern flora has nearly all its species in common with

    present floras two thousand miles to the south, we have a fact so impressive

    017      |      Vol_V-0300                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    that nearly everyone accepts it as climatic evidence. The evidence is

    rather less impressive, but of the same kind, when an early Tertiary flora

    (e.g., the London clay flora) is shown to have to bulk of its genera in com–

    mon with the Malayan flora.

            In the Mesozoic, where one can only identify a modern genus here and

    there, the evidence is so slight that, except at the end of the period, few

    regard it as evidence at all. Thus we cannot use the fact that some of the

    Mesozoic ferns are today tropical, still less that there were a good many

    Mesozoic cycads (in the strict sense) and cycads are today more or less t y ro pical.

    (The bulk of the plants called fossil cycads are the unrelated and extinct

    Bennettitales. [ ?] ) Exactly the same evidence, but with a different selection of

    Mesozoic plants ( Cinkgo , Taxus ), would suggest a temperate climate. We are

    thus forced to rely on other evidence not involving identification with living

    forms. This is largely obtained in two ways: by morphological and anatomical

    studies, and by comparison of one flora with others in the same period.

            Evidence from Morphology and Anatomy . Large tree [ ?] leaves suggest a

    favorable climate, thin cuticles a humid growing season. This of course

    assumes that plant tissues of the Mesozoic were about as susceptible to damage

    as those of today. It has already been said that fairly large tree leaves

    occur in these floras. On the other hand, there is no sign of leaves of gi–

    gantic size such as occur in a good many tropical trees, unless we include

    the various cycadalean and bennettitalean leaves which are sometimes very large.

    These large leaves may, however, equally well belong to herbaceous plants.

            The cuticles do not provide any indication of temperature, but only of

    the humidity of the growing season. All we can say is that in the Rhaeto-Liassic

    flora of East Greenland most of the abundant species, especially of conifers,

    018      |      Vol_V-0301                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    are thinly cutinized or have cuticles of only medium thickness. Thick cuticles

    occur on some species but these are rare ones. The Ginkgoales, however, as [ ?] a

    family have rather thick cuticles in this as in other floras. Thickly cuti–

    nized Ginkgoales are prominent in the Spitsbergen Lower Cretaceous floras.

            In the Greenland Cretaceous flora and in the Alaskan flora, medium-sized

    tree leaves occur which are comparable with those met in temperate forests

    today, but which, it must be admitted, are very abundant in the tropics also,

    though these fossil floras include an additional element of very large oval

    leaves which are rather foreign to temperate floras. Neither flora would seem

    to give much more than a suggestion of at least a temperate climate, but

    nothing to show whether it was cool or warm temperate, or even to exclude a

    tropical climate. We must bear in mind our ignorance of the aspect of a true [ ?]

    tropical flora in Upper Cretaceous times.

            Noting whatever is known about the cuticles of the Alaskan flora. Some–

    thing is known about those of the Greenland Cretaceous one; the bulk of the

    species seem to have thin or medium cuticles.


    Comparison of Floras in the Same Period

            It is a striking fact that many Mesozoic determinations stand close in–

    vestigation by new types of evidence and are strongly confirmed by it. Many

    Mesozoic species are thus real and recognizable, though usually only with cer–

    tainty by microscopic investigation. Unfortunately the number of floras in

    which a large proportion of the species have been microscopically examined

    is few for any period; there happen to be several in Liasso-Rhaetic times, but

    later on there is at most one for each main period, so we are not yet helped.

    Without microscopic study, Mesozoic plant determination has such a large

    019      |      Vol_V-0302                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    element of doubt that the universal distribution of Mesozoic, and particu–

    larly Jurassic, plants is still a controversial subject.

            Of the Rhaeto-Liassic period we have large floras in East Greenland,

    southern Sweden, and southwestern Germany that have been suitably investi–

    gated; this to some extent is illuminating other floras not yet so studied.

    Already some studies have been made of cuticles in Rhaeto-Liassic plants of

    China and Japan.

            From this we can say that in East Greenland at latitude 70° N. and in

    Sweden at latitude 57° N. there were almost identical floras — identical

    Rhaetic floras being succeeded by identical lower Liassic floras. In south–

    west Germany the same succession occurred, and the floras all had much in

    common, but the German one was not so similar to the Greenland and Swedish

    ones as they were to one another; for example the genus Thinnfeldia is very

    abundant in Germany but rare or almost absent in the other floras. If floras

    indicate climate, the climates of East Greenland and southern Sweden should

    have been identical, but that of southwestern Germany rather different. If

    we are to go further we must descend to weaker evidence from floras not yet

    investigated in detail. The sweden-Greenland type of Rhaeto-Liassic flora

    seems to have occurred in Poland and perhaps in China; at least, elements

    agreeing perfectly occur in both those countries and in Japan at latitude 35° N.

    Much more doubtfully, we can trace a chain of floras from Germany (lat. 50° N.)

    through Persia (lat. 35° N.) to Tonkin at latitude 20° N.

            These chains of floras are roughly parallel and have a remarkable obliquity

    in relation to present latitude. If such distribution could be substantiated,

    [ ?] it would indicate something very extraordinary — say a major shift of the

    earth’s axis or of the earth’s crust (continental drift). Unfortunately it

    020      |      Vol_V-0303                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    is not yet substantiated. In the first place, none of the determinations

    in the Persian, Tonkin, and several other floras have so far been confirmed

    by cuticles; and, much more serious, this obliquely running belt of Rhaeto–

    Liassic floras includes nearly all the known Rhaeto-Liassic floras of the

    Northern Hemisphere, which fact alone forces the species to have an oblique

    distribution, though not of course making a northern and a southern flora

    stay distinct.

            In this sweeping away any constructive suggestion from this instance,

    the author would nevertheless emphasize that he considers the method sound;

    it is the evidence that is feeble. He beli e ves that the establishment of

    floral belts in past times gives by far the best hope of working out past

    plant geography and past climate.

            So much for the evidence; it is clearly still inadequate although it

    does indicate a very different world. This being the case, theory cannot be

    expected to wait, and has not done so. The ideas expressed range between two

    extreme views. According to one view, climates have been nearly stable, but

    plants have changed — or, to speak crudely, luxuriant plants were once tough

    enough to endure arctic rigor, but many of them, becoming increasingly tender,

    were progressively exterminated in the northern part of their range, surviving

    today perhaps only in Indo-Malaya.

            By the other view plants — as, for example, palms — were always phy–

    siologically much as they are now, and consequently, if they occur as fossils,

    must indicate a climate without any severe cold, and indeed with considerable

    warmth over much of the year.

            The first view implies that p a leobotanical evidence is not of a nature

    to help [ ?] elucidate the problem of part climate and finds favor with few

    021      |      Vol_V-0304                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    paleobotanists. The second leads straight to the conclusion that the Mesozoic

    climate was mild over the Arctic generally, and invites at once the question —

    by that cause could this be so? There are a good many quite different answers,

    each of which can apparently be demonstrated to fail or be unlikely to be true

    in the light of what appears to be fact.

            Among advocates of particular theories may be mentioned Berry (3) (who

    also gives a valuable summary of evidence); and the famous work of Kőppen and

    Wegener (30). A general account (not particularly of the Arctic) favoring

    no special theory is given by Scott (44), and there are older accounts of

    some historical interest by Nathorst (35) and Seward (47).

    022      |      Vol_V-0305                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany


    1. Arnold, C.A. “Microfossils from Greenland Coal,” Mich. Acad. Sci., vol.15,

    p.51, 1931.

    2. Backlund, H. “On Fossil Plants from Solitude (Enhomhed) Island,” Geologiska

    Főreningen, Stockh. Főrh . vol.38, pt.4, 1916.

    3. Berry, E.W. “The past climate of the North Polar region,” Smithson. Misc .

    Coll . vol.82, no.6, 1930.

    4. Drygalski, E. “Grőnland,” Expedition der Gesellschaft fűr Erdkunde zu Expedition der Gesellschaft fűr Erdkunde zu

    Berlin Berlin , 1897.

    5. Florin, R. “Die Forsilen Ginkgophyten von Franz-Joseph-Land nebst erőr–

    terungun űber vermeintleieke Cordaitales mesozoiscken Alters. I,”

    Palaeontographica vol.81, B, p.71, 1936.

    6. ----. “----. II,” Ibid ., vol.82, B, p.1, 1936.

    7. ----. “On the Geological history of the Sciadopitinere,” Svensk. Bot .

    Tidskr . vol.16, p.260, 1922.

    8. Gothan, W. “Die Fossile Hőlzer von Konig Karls Land,” Svensk Vetenskap–

    sakad. Handl . vol.42, no.10, 1907.

    9. ----. “Die Fossile Holzreste von Spitzbergen,” Svensk Vetenskapsakad.

    Handl . vol.45, no.8, 1910.

    10. Harris, T.M. “The fossil flora of Scoresby Sound, East Greenland. 1,”

    Medd. Grønland , vol.85, no.2, 1931.

    11. ----. “----. 2,” Ibid . vol.85, no.3, 1932.

    12. ----. “----. 3,” Ibid . vol.85, no.3, 1932.

    13. ----. “----. 4,” Ibid . vol.112, no.1, 1935.

    14. ----. “----. 5,” Ibid . vol.112, no.2, 1937.

    15. ----. “Liassic and Rhaetic plants collected in 1936-38 from East

    Greenland,” Ibid . vol.114, no.9, 1946.

    16. ----. “A new member of the Caytoniales,” New Phyto . Vol.32, p.97,


    17. ----. “The Rhaetic flora of Scoresby Sound, East Greenland,” Medd .

    Grønland , vol.68, p.43, 1926.

    023      |      Vol_V-0306                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    18. Hartz, N. “Planteforsteinger fra Cap Sewart i Ostgronland, med. en

    historisk Oversigt,” Ibid . vol.19, p.217, 1896.

    19. Heer, O. “Beiträge zur fossilen Flora Spitzbergens,” Flora Foss. Arct .

    vol.4, 1876.

    20. ----. “ Flora Fossilis Groenlandica,” Ibid . vol.6, 1882.

    21. ----. “Flora Fossilis Groenlandica 2,” Ibid . vol.7, 1883.

    22. ----. “Die Keide Flora der Arctischen Zone.” Svenska Vetenskapsakad.

    Handl . vol.12, no.6, [ ?] 1874.

    23. ----. “Nachtrage zur fossilen Flora Gronlands,” Flora Foss. Arct .

    vol.6, 1880.

    24. [ ?] Hollick , A. “The Upper Cretaceous floras of Alaska,” U.S.Geol.Surv.

    Prof. Pap . no.159, 1930.

    25. Horn, G. “Beiträge zur Kenntris der Kohle von Svalbard,” Norsk Polar–

    institutt, Skr . no.17, 1928.

    26. Johnsson, N. “Neue Mesozoische Pflanzenaus Andö in Norwegen,” Svensk .

    Bot. Tidskr . vol.14, p.249, 1920.

    27. Knowlton, F.H. “The Jurassic Flora of Cape Lisburne, Alaska,” U.S.Geol.

    Surv. Prof. Pap . no.85, 1914.

    28. ----. “A lower Jurassic flora from the upper Matanuska Valley, Alaska,”

    U.S.Nat. Mus. Proc . vol.51, no.2158, 1916.

    29. Koch, L. “Stratigraphy of Greenland,” Medd. Grønland , vol. [ ?] 73, 1929.

    30. Köppen, W., and Wegener, A. Die Klimate der geologischen Vorzeit . Berlin,


    31. Lundblad, B. “A selaginelloid strobilus from East Greenland (Triassic),”

    Dansk. Geol. Foren. Medd , vol.11, pt.3, 1948.

    32. Martin, G.C. and Katz, F.J. “A Geologic reconnaissance of the Iliamna region

    of Alaska,” U.S.Geol.Surv. Bull . 485, 1912.

    33. Miner, E.L. “Megaspores ascribed to selaginellites, from the Upper Cre–

    [ ?] taceous coals of Western Greenland,” Wash.Acad. Sci. J . vol.22,

    no.18, 19, 1932.

    34. ----. “A new Gleichencopsis from the Upper Cretaceous of western

    Greenland,” Amer. J. Bot . vol.21, no.5, 1934.

    024      |      Vol_V-0307                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    35. Nathorst, A.G. “Fossil floras of the arctic regions as evidence of

    geological climates,” Geol. Mag . Lond. 5, vol.8, p.217, 1911.

    36. ----. “Fossil Plants from Franz Josef Land.” The Norwegian Polar

    Expedition 1893-96. Scientific Results . III. London and

    Christiania, 1899.

    37. ----, “Palaeobot. Mitteilungen. Pseudocyca, ein neue Cycadophyten

    gattung aus den Cenomanen Kreideablagerungen Grőnlands,” Svenska

    Vetenskapsakad. Handl . vol.42, no.5, 1907.

    38. ----. “Die Pflanzenfuhrenden Horizonte innerhalb der Grenzschichten

    des Jura und eter Kreide Spitzbergens,” Geologiska Főrsningen,

    Stockh. Főrh . vol.35, pt.4, 1913.

    39. ----. “Ueber die Reste eines Brotfruetbaums, Artocarpus Dicksoni ns.p.,

    Aus. Den Cenomanon Kreideablagerungen Grønland,” Svenska

    Vetenskapsakad. Handl . vol.24, no.1, 1890.

    40. ----. “Ueber Nathorstia,” Ibid . vol.43, no.6, 1908.

    41. ----. “Ueber Trias- und Jurapflanzen von der Insel Kotelny,” Akad.

    Nauk. Classe Phys. -Mat. Mem. Zapiski , ser.8, vol.31, no.2, 1906.

    42. ----. “Zur Mesozoischen Flora Spitzbergens,” Svenska Vetenskapsakad.

    Handl . vol.30, no.1, 1897.

    43. Newton, E.T. and Teall, J.J.H. “Notes on a collection of rocks and fossils

    from Franz Joseph’s Land, made by the Jackson Harmsworth Ex–

    pedition during 1894-1896,” Geol. Soc. Lond. Quart. J . vol.54,


    44. Scott, W.B. Geological Climates. Smithsonian Inst. Report 1927, pp.271-87,


    45. Selling, O.H. “A Megaspore from the Mesozoic of Hope Island, Svalbard,”

    Botaniska Notiser , 1945, pt. 1, p.44, 1945.

    46. ----. “On Cupressoid Root Remains of Mesozoic Age from the Arctic,”

    Arkiv. f őr Bot . vol.31A, no.13, 1944.

    47. Seward, A.C. “Arctic vegetation past and present,” Roy. Hort. Soc. J .

    Lond. vol.50, pt. 1, 1925.

    48. [ ?] ----. “The Cretaceous plant-bearing rocks of western Greenland,”

    Roy. Soc. Lond. Philos. Trans . vol.215, p.57, 1926.

    49. ----. “The Jurassic Flora of Sutherland,” Roy. Soc. Edinb. Trans . vol.

    [ ?] 47, IV, 1911.

    025      |      Vol_V-0308                                                                                                                  
    EA-PS. Harris: Mesozoic Paleobotany

    50. Seward, A.C. “Notes sur la Flore Cr e é tacique du Groenland. Etude critique.”

    G e é ol. Soc. Belgique, Livr. Jub ., p.229, 1925.

    51. ----., and Conway, V. “Additional Cretaceous plants from western

    Greenland,” Svenska Vetenskapsakad. Handl . ser.3, vol.15, no.3,


    52. ----, and ----. “Fossil plants from Kingitok and Kagdlunguak,

    West Greenland,” Medd. Grønland , vol.93, no.5, 1935.

    53. Solms-Laubach, Graf Zu. “Die structurbeitenden Pflanzengesteine von Franz

    Josefs Land,” Svenska Vetenskapsakad. Handl . vol.37, no.7, 1904.

    54. Stopes, M.C. “The flora of the Inferior Oolite of Brora (Sutherland),”

    Geol. Soc. Lond. Quart. J . vol.63, 1907.

    55. Tutin, T.G. “A Cretaceous Gleicheniaceous fern from western Greenland,”

    Ann. Bot . vol.46, p.503, 1932.

    56. Walton, J. “On some fossil woods of Mesozoic and Tertiary age from

    the arctic zone,” Ibid . vol.41, 1927.

    57. White, D. and Schuchert, C. “Cretaceous series of the western coast of

    Greenland,” Geol. Soc. Amer. Bull . vol.9, 1897.


    Thomas W. Harris

    Arctic Forests of the Cenozoic

    Unpaginated      |      Vol_V-0309                                                                                                                  
    EA-Plant Sciences

    (Ralph W. Chaney)




    Introduction 1
    Metasequoia 3
    Tertiary Forest Zones 5
    Cool Temperate Floras 6
    Temperate Floras 9
    Floras Transitional to Warm Temperate 13
    Summary of the Tertiary Forest Record 15
    Pleistocene Vegetation 20
    Conclusion 21
    Bibliography 22

    Unpaginated      |      Vol_V-0310                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic



            With the manuscript of this article, the author submitted 4

    photographs for possible use as illustrations. Because of the high

    cost of reproducing them as halftones, they will not be used. All

    photographs are being held at the Stefansson Library.

    001      |      Vol_V-0311                                                                                                                  
    EA-Plant Sciences

    (Ralph W. Ch e a ney)





            The widespread occurrence of anglosperms and conifers in Cenozoic

    rocks provides an increasingly sound basis for our identification of the

    plants which lived during the past seventy million years, and for the

    reconstruction of the habitats which they occupied. These plant fossils

    closely resemble many of the trees now living, as shown by the abundant

    impressions of their leaves, and by accompanying remains of seeds, pollen,

    and stems. The modern aspect of Cenozoic vegetation is further illus–

    trated by the intimate association in the rocks of many genera which are

    still found living together. Whereas the plants of the Paleozoic era, and

    those of most of the Mesozoic, are largely of types no longer in existence,

    the dawn of modern life at the beginning of the Cenozoic era has provided

    familiar kinds of trees whose relationships may be readily established.

    So we may turn to living forests, made up of genera which have survived

    down to our day, to find answers to many questions regarding the environments

    of the past. The answers to such questions are particularly significant in

    a study of arctic vegetation, for these forests of past ages ranged into

    latitudes beyond the northern limits of present-day trees.

            Arctic exploration during the past hundred or more years has resulted

    002      |      Vol_V-0312                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    in the discovery of many localities where Cenozoic plants are well preserved.

    Most of the collections brought back by early explorers were of necessity

    meager, and the Europeans who studied them, Goeppert and Heer, did not

    always have a sound basis for the conclusions they reached. In later years

    additional material has become available, especially in Greenland and Alaska;

    we are now in a better position to determine what kinds of trees made up

    these forests, and to describe the climatic and other environmental factors

    which made possible their existence at high northern latitudes.

            All of the Cenozoic floras which have so far been found in the Arctic

    are referred to the early stages of the Tertiary period. Future discoveries

    may provide evidence of still younger floras there, but for reasons which

    will be discussed below we have little basis for supposing that the more

    northerly localities have had a climate suitable for tree growth during

    the past twenty-five million years, or from the Miocene down to the present.

    Opinions differ as to the relative age of the Tertiary floras from several

    areas, but we shall here assume that all of them are of approximately the

    same age, and that they lived during the Paleocene and Eocene epochs. The

    principal regions of occurrence are northern Siberia, the New Siberian

    Islands, Alaska, northern Canada including the Arctic Archipelago, western

    Greenland, Iceland, and Spitsbergen. A survey of the plants represented in

    these localities indicates that there are well-marked differences in composi–

    tion from north to south which are strongly indicative of climatic zones.

    On the other hand, an abundant genus, Metasequoia , has been recorded from

    Tertiary floras through a wide range of arctic latitudes. Earlier misidenti–

    fications of this conifer have been in large measure responsible for several

    misconceptions regarding the character of Tertiary forests in the Far North,

    003      |      Vol_V-0313                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    and the climate under which they lived. It therefore seems desirable at

    this point to consider the present status of Metasequoia, the dominant

    conifer of the Tertiary period not only at high but at many middle latitudes

    in the Northern Hemisphere.



            Only a few years ago Miki made the announcement that certain conifer

    fossils previously referred to Sequoia and Taxodium from the Tertiary of

    Japan were properly referable to a distinct genus, to which he gave the name

    Metasequoia (1941); the principal distinguishing characters indicated were

    the decussate arrangement of the leaves and cone-scales, and the attachment

    of the cones on naked stalks. Three years later living trees with similar

    foliage and cones were found by Tsang Wang in Szechuan, China; an announce–

    ment of this discovery was made by Hu in a paper in which he assigned a

    fossil from Manchuria, originally described as Sequoia , to Metasequoie (1946).

    A full description of these trees and of their occurrence in central China

    soon appeared in a paper by Hu and Cheng (1948). By this time, through the

    interest and support of Merrill, seeds had been widely distributed in North

    America and Europe, and many of them had been successfully germinated.

    Early in 1948, Chaney and Silverman visited the valleys in Szechuan and

    Hupeh where Metasequoia had survived; here it was apparent that most of the

    trees living in association with it were members of genera with which it had

    been found in rocks of Cretaceous and Tertiary age (Chaney, 1948: 510).

    More detailed studies of the ecology of living Metasequoia , subsequently

    made by Chu and Cooper (1950), confirm this discovery. A detailed survey

    of all the fossil material described under the name of Sequoia and Taxodium

    004      |      Vol_V-0314                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    in North America, and reference to illustrations of specimens of these

    genera found elsewhere in the Northern Hemisphere, has been made by Chaney,

    who concludes that most of the conifer remains from temperate North America

    and Asia, and from all the arctic localities, are properly referable to

    Metasequoia (1950). Only in western Europe ( S. langsdorfii ) and at scattered

    localities in the United States ( S. affinis ) is Sequoia a dominant conifer,

    and in the United States Taxodium ( T. dubium ) exceeded Metasequoia in abundance

    only during the [ ?] Miocene (Chaney, 1949; 127).

            This revision comes to be more than a matter of nomenclature when it is

    realized that the redwood of China ( M. glyptostroboides ) has a deciduous habit,

    unlike its close relative, the coast redwood ( S. sempervirens ). A further

    significant habit difference may be seen with another close relative, the

    swamp cypress ( T. distichum ), for Metasequois seems able to survive in regions

    with severe and prolonged winters. (This statement is based upon the successful

    planting of Metasequoia seedlings in many areas beyond the northern limits of

    Taxodium , and as far north as southeastern Alaska.) Here is a tree which has

    shown itself to be hardy at high latitude on the basis of preliminary plantings,

    and which also grows well under milder climatic conditions as far south as

    Mexico and Florida. A correspondingly wide range of habitats has been pointed

    out for the Tertiary representative of Metasequoia , M. occidentalis , which is

    found associated in fossil floras with trees whose modern habitats range from

    warm temperate to cool temperate (Chaney, 1949a). The conclusion that

    Metasequoia was dominant at high latitudes during Cenozoic time, and in the

    Cretaceous as well, provides a tree admirably suited by its deciduous habit for

    living in a region of long, though perhaps not extremely cold, winters. Assumption

    of mold climate such as that now required by the coast redwood is no longer

    005      |      Vol_V-0315                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    necessary for high northern latitudes during later geologic time; no

    Sequoia of the distichous type is known to have lived beyond southern

    Alberta and Montana during the past. ( Sequoia ( Sequoiadendron ) with spirally

    disposed leaves like those of the living S. gigantea ranged farther north in

    the past, but like its modern relative may be supposed to have been suited

    to wider extremes of temperature.) Not even Taxodium , which like Metasequoia

    has a deciduous habit, [ ?] is known to occur in the fossil record at the most

    northerly localities. From Grinnell Land south to the northern United States,

    Metasequoia was the dominant conifer of the Cenozoic forest, as judged by the

    abundance of its foliage and cones in the fossil record.



            The vegetation which lived at high northern latitudes during the early

    epochs of the Cenozoic era is commonly referred to as the Arcto-Tertiary Flora.

    From this name it should not be concluded that all of the genera represented

    had their origin during the Tertiary period, for many of them appeared during

    the preceding Cretaceous period; nor are we justified in the inference of an

    exclusively arctic origin for this major floral unit, for some of its members

    appear also to have lived at lower latitudes during the early days of the

    Cenozoic. However the use of the designation “Arctic Tertiary” is highly

    appropriate with reference to this early Cenozoic vegetation of the North,

    in view of its widespread distribution there, and of its southward migration

    during later Tertiary epochs; large segments of the Arcto-Tertiary Flora still

    survive in many parts of the Northern Hemisphere, especially in middle latitudes.

            The outstanding feature of the Arcto-Tertiary Flora, both past and modern,

    is its mixture of broad-leafed deciduous trees with conifers, both deciduous

    006      |      Vol_V-0316                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    and evergreen. But an alysis of the early Cenozoic vegetation from various

    localities in the Arctic indicates that it varied as widely from place to

    place, and especially at different latitudes, as do the forests of today.

    We shall therefore consider the record of these ancient forests with reference

    to the climatic types which are represented. The location of the fossil

    localities is shown on the accompanying map (Figure 1). Table I gives

    lists of the principal general from the several localities; these include only

    the better known and reliably identified woody plants.


    Cool Temperate Floras

            Floral units of this type are found in the interior of Siberia and

    Canada, and on the most northerly of the islands of the Arctic Sea with the

    exception of Spitsbergen. For reasons considered below, the Tertiary flora

    of Spitsbergen is of a typically temperate type, with a much larger assemblage

    of genera than is found at corresponding latitudes elsewhere. The following

    localities contain representatives of the cool temperate forest, including

    such typically northern families as the Pinaceae, Salicaceae, and Betulaceae,

    and three genera now restricted to northeastern and central Asia, Ginkgo ,

    Metasequoia , and Cercidiphyllum .

            Interior of Siberia . A small collection studied by Heer (1878) from

    Tsohirimyi on the Lena River (lat. 65° 30′ N.), includes a fern ( Asplenium ),

    leaves of Ginkgo , numerous foliage shoots of Metasequoia (by him referred to three

    species of Taxodium ), [ ?] foliage shots of a more scaly type which may be

    assignable to Sequoiadendron (by him referred to Sequoia ) and fragmentary

    leaves of angiosperms, two of which seem to represent Cercidiphyllum crenatum

    (his Populus arctica ? and Paliurus colombi ). Fragmentary angiosperm leaves

    007      |      Vol_V-0317                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    from Tas-takh Lake are mentioned by Kryshtofovich (1929) as referable to

    poplar and walnut, and it seems probable that the former would now be

    recognized as Cercidiphyllum . Still farther north on the Taimyr River

    (1868), Heer recognized only foliage resembling pine (pinites).

            New Siberian Islands . Similar plants have been described by Schmalhausen

    (1890) from latitude 76° N. A fern ( Aspidium ), Metasequoia represented by

    foliage and cones, another conifer considered to represent Pinus, and

    Cercidiphyllum crenatum ( Populus richardsoni ) are all that can be surely

    recognized from the material figured, with fruits named Nyssidium geminatum

    possibly representing Cercidiphyllum . Coniferous wood, some of which resembles

    that of Metasequoia , is also figured.

            Mackenzie Valley . In his first volume of Flora Fossilis Arctica (1868),

    Heer included a brief discussion of the occurrence of material collected by

    Richardson in the Mackenzie Basin at 65° N. latitude, near the mouth of Great

    Bear River. Several species are based on material so fragmentary as to give

    no adequate basis for their generic identification; I recognize Metasequoia ,

    Populus , Salix , Betula , and Cercidiphyllum , all of which are members of other

    cool temperate floras. In a second paper (1880), to which were added specimens

    collected by the Hudson’s Bay Company, Heer listed several additional genera;

    but the specimens of Juglans , Platanue , Magnolia , Tilia , and Viburnum which

    he figured can scarcely be considered convincing evidence of their occurrence.

    The genera cited above appear to represent all that can be recognized with

    any certainty.

            Banks Island . Cones referable to spruce ( Picea ) were assigned by Heer

    (1868) to Pinus ( Abies ) macclurii , and wood specimens studied by Cramer, to

    the form genus Cupressinoxylon , and to birch ( Betula macclintockia ). The

    latitude of this occurrence is 740 N.

    008      |      Vol_V-0318                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

            Bathurst Island . Fragmentary needles referred by Heer (1868) to pine

    ( P. bathursti ) represent the only plant remains known from this locality

    (latitude 76°N.). They appear to resemble spruce rather than pine, but

    are not well enough preserved to establish the presence of either genus.

            Southern Ellesmere Island . The foliage of Metasequois figured by

    Nathorst (he called it Sequoia) from this locality (latitude 77° 20′ N.)

    is extremely well preserved; wood referable to Metasequoia is also recorded

    (1915). It seems rather unlikely that the foliage shoots referred to

    Glyptostrobus are correctly identified in view of its present restriction

    to southeastern China. However, they resemble Glyptostrobus , and the Tertiary

    occurrence of this genus elsewhere at high northern latitudes suggests the

    possibility of its wider temperature tolerance in the past. Fragments of

    dictoyledonous leaves resemble those of Cercidiphyllum .

            Grinnell Land . This northernmost Tertiary flora, at latitude 82° N., is

    also the largest in the group here considered to represent a cool temperate type

    of vegetation. Heer’s list of species (1878) contains many apparent misidenti–

    fications, as pointed out by Berry (1922: 9). Our revision, based upon an

    examination of the figures in Flora Fossilis Arctica , includes only the genera

    whose presence seems clearly established: Equisetum , Picea (or Abies ), Pinus ,

    Metasequoia , indeterminate grasses and/or sedges, Betula , Cercidiphyllum .

    To these may probably be added to water lilly, Nymphaea , which is represented

    by characteristic roots; Salix and Populus , which is represented by charac

    teristic listed by Heer, are wholly in place in this assemblage, and it is

    possible [ ?] that some of his specimens may represent these genera (see pl.8,

    figs. 8, 6).

    009      |      Vol_V-0319                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic


    Temperate Floras

            These floras, for the most part of more southerly occurrence than the

    preceding, are made up of plants which are typically temperate in their

    modern distribution. Among the common families are the Pinadeae, Taxodiaceae,

    Salicaceae, Betulaceae, Juglandaceae, Fagaceae, Ulmaceae, Platanceae,

    Aceraoeae, and Cercidiphyllaceae. Grasses and sedges are well represented

    in several units. All of the genera known to occur farther north have

    been recorded here, together with many others which are widespread in

    Tertiary floras of later age and at lower latitudes. This unit constitutes

    the typical Arcto-Tertiary Flora which has survived in modified form in

    so many areas of the Northern Hemisphere. Like those of the cool temperate

    type, these floras contain a mixture of deciduous angiosperms and conifers,

    as well as some evergreen conifers.

            Iceland . This small [ ?] flora, as described by Heer (1868), is typically

    temperate. It is significant to note that Metasequoia is not recorded, nor

    is it known from the adjacent Tertiary floras of western Europe. It is

    impossible to determine from Heer’s figures what conifer is represented by

    his Sequoia sternbergi ; it is surely not a member of the Taxodiaceae, but

    may be Abies , Picea , or both; some of the seeds figueed as Pinus seem

    clearly referable to Abies ; other seeds appear to represent Pinus . In

    addition to sedges and aquatic plants, there are recorded willow ( Salix ),

    walnut ( Juglans ), several members of the Betulaceae and Fagaceae, and such

    common genera as sycamore ( Platanus ) and maple ( Acer ). It is probable that

    this list will be greatly supplemented when more recently made collections

    have been studied.

            Spitsbergen . The occurrence of plant fossils at this northerly locality

    010      |      Vol_V-0320                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    (lat. 77° 30′ to 78° 5′ N.), in Eocene strata associated with coal, has

    long been known; Heer presented the results of his preliminary study in

    Volume I of Flora Fossilis Arctica (1868), and in ensuing years added other

    species to the list (1871, 1876). The flora is smaller than those from

    Alaska and Greenland, but includes most of the temperate genera which

    characterize these floras to the south. Among the common families are the

    Taxodiaceae, Salicaceae, Betulaceae, Fagaceae and Cercidiphyllaceae.

    Glyptostrobus and Magnolia suggest a fairly mild temperature. Grasses

    and sedges are unusually abundant. Plate 1 shows a specimen from the

    collections of the United States National Museum; on this slab of carbona–

    ceous shale, collected by Schuchert and White on Advent Bay, are many

    foliage shoots of Metasequoia , together with leaves of walnut and birch.

            Northeastern Siberia . In his paper on the Tertiary Flora of the Korf

    Gulf, Kamchatka (1934), Kryshtofovich gives a summary of current knowledge

    of the vegetation of this general region. Goeppert (1867) first described

    a small flora including Metasequoia ( Taxodium ), Carpinus , Alnus , and Juglans .

    Nathorst published a list based on collections from Kamchatka by Dubovsky

    in his paper on the fossil floras of Japan (1888), with the following genera:

    Equisetum. Metasequoia ( Sequoia ), Salix , Populus , Alnut , Acer , Cercidiphyllum

    ( Populus ), Fraxinus , and Cornus . Palibin’s list from the Commander Islands

    (1905) includes a species of Sequoia which is now known to represent

    Taxodium in part and may also be assignable to Metasequoia ; he also

    reports the occurrence of Glyptostrobus , Thuites , two grasses, and leaves

    referred to Cinnamomum which Kryshtofovich considers to have a doubtful

    status. The flora of the Anadyr River, as listed by Kryshtofovich and

    assigned to the Paleocene (in an undated paper) includes the following

    011      |      Vol_V-0321                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    trees and shrubs: Metasequois (under the names Taxodium and Sequoia ),

    Glyptostrobus , Alnus , Acer , Cercidiphyllum ( Populus , Vitis , and Nyssa .

    All are common members of other high latitude Tertiary floras, but without

    referenced to his material it is impossible to confirm these determinations.

    The Korf Gulf flora itself is the largest and most adequately illustrated

    from this area, though several of Kryshtofovich’s figures are not convincing.

    He indicates his opinion that it is of Oligocene age, but there appears to

    be little basis for separating it from other Eocene floras of adjacent regions

    and latitudes. In addition to Equisetum and a fern, he lists a total of 24

    forms, all of which fall in the temperate families above mentioned. It is

    difficult to tell from the illustrations whether all of his genera are

    actually represented; a leaf doubtfully referred to Quercus seems not to

    be assignable to that genus, and some question may be raised regarding the

    leaves referred to Carya and Celtis ; but the majority of Kryshtofovich’s

    generic identifications seem to be sound.

            Alaska . The Tertiary floras of Alaska received their first comprehensive

    treatment in Heer’s second volume of Flora Fossilis Arctica (1871). Extended

    study by Knowlton and Hollick has provided material for a more recent publica–

    tion in which Hollick considered their age to be Eocene (1936). He recognized

    350 forms, including an alga, 13 ferns, and 2 species of Equisetum ; among

    the gymnosperms he describes 3 cycads, 2 species of Ginkgo , and 26 conifers;

    angiosperms make up the remainder of the flora, with 14 monocotyledons and

    288 dicotyledons, and with an additional 10 species assigned to form genera.

    Many of Hollick’s genera do not seem to be properly identified, and he

    seems to have recognized too many species in certain genera; however, there

    is a sufficient number of well-characterized forms to provide an adequate idea

    012      |      Vol_V-0322                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    of the forests which lived in Alaska during the Eocene. Since the plants

    recorded from several regions and latitudes show significant differences,

    I shall consider them in four groups, starting at the north.

            The Bering Sea Region . Collections on St. Lawrence Island and the

    adjacent mainland have been made in recent years under my direction.

    Material brought down from St. Lawrence Island (lat. 63° 30′ N.) by Collins

    and Jones includes Metasequoia , Alnus or Betula , Platanus , and probably

    Cercidiphyllum (Chaney, 1934). A larger collection made by Mason has never

    been described. The occurrence here of Platanus is of interest, since it is

    a typically temperate genus at the present time. On the opposite mainland,

    at Coal Creek in the Norton Sound area, Mason collected Taxodium , Platanus ,

    and leaves which probably represent Diospyros .

            The Yukon Basin . In central Alaska fossil plants have been collected in

    the valley of the Yukon from latitude 65° nearly to 66° North, and southward

    in the drainage of the Tanana River to about latitude 63° N., as ma n y be

    seen on the charts and map in Hollick’s Professional Paper . The common

    families are Pinaceae, Taxodiaceae, Salicaceae, Juglandaceae, Betulaceae,

    Fagaceae, Cercidiphyllaceae, Platanaceas, and Aceraceae. All the genera

    have living species in temperate regions, with Diospyros the only genus

    whose modern range is largely in the tropics.

            Central Alaska . ( Alaska Peninsula and Cook Inlet Region ). The florules

    collected from latitude 56° N. in the Alaska Peninsula northeastward to the

    Matanuska Valley, at nearly latitude 62° N., have essentially the same compo–

    sition. They appear to represent an assemblage intermediate between that

    of the Yukon Basin and southeastern Alaska, with many genera in common on

    both sides; and with oaks more numerous than elsewhere. Although dominantly

    013      |      Vol_V-0323                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    temperate in aspect, this intermediate flora includes several plants

    which now range into southern regions, such as swamp cypress ( Taxodium ),

    water pine ( Glyptostrobus ), palm ( Flabellaria ), magnolia ( Magnolia ), sweet

    gum ( Liquidambar ), laurels ( Lindera and Persea ), and persimmon ( Diospyros ).


    Floras Transitional to Warm Temperate

            It would be going too far to state that either the flora from Kupreanof

    Island in southeastern Alaska, or that from Disko Island in western Green–

    land, are typically warm temperate in aspect. But the presence in the former

    of cycads, a palm, representatives of the Lauraceae, and Dillenia is strongly

    indicative of an ecotonal belt between the typically temperate floras in

    central Alaska and the warm temperate to subtropical floras of the northern

    United States; the Greenland flora, lying several degrees farther north, shows

    less indication of mild temperatures, but with its palms and laurels it like–

    wise bears an ecotonal relationship. Most of the trees at both localities

    were typically temperate.

            Southeastern Alaska . The most productive localities in this region are

    on Hamilton Bay at the north end of Kupreanof Island, in latitude 57° N. A

    majority of the specimens are of temperate types, in such families as the

    Pinaceae, Taxodiaceae, Salicaceae, Juglandaceae, Betulaceae, and Fagaceae;

    but in addition to the warm temperate forms above mentioned, such genera as

    Taxodium , Glyptostrobus , Zelkova , Magnolia , Diospyros , and Liquidambar are

    suggestive of moderate winter temperatures. The most abundant conifer,

    Metasequoia , is found today in a similar ecotone between the subtropical

    lowland and the temperate upland forests of central China. Plate 2 shows

    a slab of shale bearing a leaf of Dioon together with foliage shoots of

    Metasequoia . Plate 3 shows the association of this conifer with the more

    014      |      Vol_V-0324                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    temperate Alnus and Juglans .

            Western Greenland . No arctic flora has aroused such wide interest, or

    has so greatly stimulated scientific and popular imagination, as the

    collections from Disko Island, on the west coast of Greenland. Again it was

    Oswald Heer who first made known the details of this vegetation (1868, 1871,

    1874, 1880); in his final volume of Flora Fossilis Arctica (1883) he listed

    a Tertiary flora containing 282 forms; 8 of these represent fungi, and one

    a moss; 19 are ferns; there is a doubtful species of lycopod, a Psilotum -like

    plant, and an Equisetum ; 27 gymnosperms are members of the Coniferales, and

    Ginkgo is also recorded; the remaining 223 forms represent angiosperms, with

    21 monocotyledons, 182 dicotyledons, and 20 assigned to form genera. (As in

    the case of Hollick’s Alaska list, Heer’s Greenland flora shows many generic

    misidentifications and is characterized by over-speciation.)

            Whether or not all of this material comes from Tertiary horizons, or

    whether it may in part come from the older Cretaceous as has been suggested,

    is a question which can not be considered here. The occurrence of most of

    the typical species of this Greenland flora in other arctic floras recognized

    as Eocene seems to indicate that most of the fossils of this assemblage occur

    in rocks of Tertiary age. We need not consider here the unsound basis for

    Heer’s reference of this and other northern floras to the Miocene; nor will

    it be profitable to attempt any general revision of Heer’s determinations,

    involving as they did the recognition of many species on the basis of evidence

    no longer held adequate. For our purposes it will be sufficient to indicate

    that the same temperate families found elsewhere in the Arctic are abundantly

    represented, and that there is also a group whose modern [ ?] equivalents range

    into lower latitudes; this includes Zelkova , Persea , Diospyros , Liquidambar ,

    015      |      Vol_V-0325                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    Magnolia , the palm, Flabellaria , and the three widespread genera of the

    Taxodiaceae , Metasequoia , Taxodium , and Glyptostrobus .


    Summary of the Tertiary Forest Record

            The geographic distribution of the well-established and abundant genera

    recognized in the older Tertiary deposits of the Arctic is shown in Table I.

    Complete analysis of this table cannot here be attempted, but it is readily

    apparent that the floras may be divided into a relatively small northern

    group and a major southern one. Whereas the genera of the northern group

    are recorded also from the southernmost floras, the genera of the southern

    group do not range far to the north. The Arcto-Tertiary Flora of the Eocene

    is here shown to represent a homogeneous forest, limited to a few genera on

    its northern borders, and on the south setting up an ecotonal relationship

    with the warm temperate floras of lower latitudes. Fossil wood found at many

    arctic localities shows well-marked growth rings characteristic of the seasonal

    climate of temperate regions.

            Complete reliance may not be placed upon conclusions derived from a

    generic analysis, for some genera such as Pinus , Populus , and Diospyros now

    cover a wide range of latitudes and environments; other genera such as Ginkgo ,

    Metasequoia , and Glyptostrobus are so limited in their modern distribution

    as to leave some doubt as to their earlier climatic requirements. However

    there seems to be little question that forest zoning of the Arcto-Tertiary

    Flora was well developed at the beginning of the Cenozoic era, and that this

    zoning was closely related to climatic factors controlled by latitude, with

    local modification resulting from ocean currents.

            Comparison with the latitudinal occurrence of similar zones of vegetation

    in the Northern Hemisphere today (Zon and Sparhawk, 1923: map opposite p. 14;

    016      |      Vol_V-0326                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    Table I. Geographic Distribution of Tertiary Floras.
    1 2 3 4 5 6 7 8 9 10 11 12 13 14
    Ginkgo x x x x x
    Pinus x x x x x x x
    Picea x x x x x
    Metasequoia x x x x x x x x x x
    Populus x x x x x x x
    Salix x x x x x x x
    Betula x x x x x x x x
    Cercidiphyllum x x x x x x x x x x x x
    Taxodium x x x x x
    Glyptostrobus x x x x x
    Juglans x x x x x x x
    Carya x x x
    Corylus x x x x x x
    Carpinus x x x x x x
    Alnus x x x x x x x x
    Castanea x x x
    Fagus x x x x x
    Quercus x x x x x x x
    Ulmus x x x
    Zelkova x x x x
    Platanus x x x x x
    Acer x x x x x x
    Diospyros x x x
    Liquidambar x x
    Cornus x x x x
    Fraxinus x x x x
    Tilia x x
    Viburnum x x x x
    Ceratozamia x
    Dioon x
    Flabellaria x x x
    Magnolia x x x x
    Lindera x
    Persea x x x
    Sassafras x x
    Malapoenna x
    Dillenia x

    1 Siberia, interior 8 Siberia, northeastern
    2 New Siberia Islands 9 Alaska, Bering Sea
    3 Mackenzie Valley 10 Alaska, Yukon Basin
    4 Banks Island 11 Alaska, central
    5 South Ellesmere Island 12 Spitsbergen
    6 Grinnell Land 13 Alaska, southeastern
    7 Iceland 14 Greenland

    017      |      Vol_V-0327                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cen o zoic

    Munns, 1938; Kudlenok, in Balzak, Vasyutin and Feigin: 60) indicates

    their more northerly position during the Eocene epoch. The northern limit

    of the modern coniferous forest is approximately 70° N. in North America

    and Eurasia, with a northward extension to about 74° on the Taimyr Peninsula;

    the northernmost known occurrence of the cool temperate floras of the Eocene

    ( Pinus , Picea , Metasequoia , together with Ginkgo , Populus , Salix , Betula ,

    Cercidiphyllum ) is in Grinnell Land, at latitude 82° N. Tundra is now the

    prevailing type of vegetation at this and all the other cool temperate Eocene

    localities. It may be noted that Salix and Betula occur as shrubs in Spits–

    bergen, at nearly latitude 80° N.; Pinus extends to 66° in Alaska, and Picea

    to 67°; Ginkgo is reported to have lived under cultivation in Iceland;

    Metasequoia , as elsewhere stated, has been planted in southeastern Alaska

    and has survived an exceptionally cold winter; Cercidiphyllum ranges north

    into Hokkaido, and there is no reason to believe it might not grow under

    cultivation much farther north. This group of genera, while relatively

    hardy today, does not extend as far north as its known Eocene limits, though

    the discrepancies are less marked than in the case of the typically temperate

    forest [ ?] .

            Considering the present northern limits of some of the more typical

    temperate genera in North America, Platanus extends to 45° N., Juglans and

    Carpinus to 47°, Quercus to 50°, and Acer to 55°. The mixed deciduous forest,

    which includes most of the temperate unit of the Eocene, finds its northern

    limit at about 50° in North America and Asia, extending north to [ ?] 60° in

    Europe; its northernmost Eocene limits were from 60° to 65° in Alaska, Iceland,

    and Kamchatka, and reached nearly to latitude 80° N. in Spitsbergen.

            The group of southern genera, recorded from the Eocene of southeastern

    018      |      Vol_V-0328                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    Alaska and western Greenland, includes four genera which have typically

    temperate species in North America, Sassafras and Lindera which range

    north to 45°, Magnolia which reaches 43°, and Persea which extends as

    far north as 39°; all of these genera have their principal occurrence

    much farther south. The northernmost limit of palm ( Sabal ) today is at

    about latitude 35° N. Dioon and Ceratozamia are restricted to southern

    Mexico, at about latitude 20°, while Dillenia and Malapoenna occur still

    farther south. We may conclude that discrepancies between the Eocene and

    modern distribution of the several forest types are greatest in the case of

    the warm temperate genera, and least in the case of the genera making up

    the cool temperate unit. Similar space relations for the Arcto-Tertiary

    Flora in northeastern Asia have been noted from the Eocene to the present.

    (Chaney and Hu, 1940: 126-134).

            When we survey the older Tertiary vegetation at middle latitude in

    Eurasia and North America, it becomes apparent that other zones occupied

    by warm temperate and subtropical forests lay to the [ ?] south, in

    middle latitudes which are today occupied by temperate forests. Durham has

    shown (1950) that tropical marine faunas lived as far north as Washington

    during Eocene time, and has concluded from the study of faunal distribution

    that “during the Cenozoic the continents and poles must have been in approxi–

    mately the same positions as at present.” This conclusion is fully confirmed

    by the distribution of Eocene vegetation, as outlined in an earlier paper by

    the writer (1940: 481-486). Reference to the map of distribution (Figure 1)

    will show that the cool temperate floras of the Eocene have a more southerly

    position in the continental interiors (Siberia, Mackenzie Basin) than in the

    Arctic Archipelago where the moderating influence of ocean currents from the

    019      |      Vol_V-0329                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    south brought milder winter temperatures. The bending northward of

    temperate forest distribution (temperate isoflor) may best be seen in the

    case of Spitsbergen, which must during the Eocene, as now, have held a

    [ ?] position north of the major seaway between Greenland and Norway.

    A smaller seaway through Davis Strait appears to have been responsible for

    the northward extension of the warm phase of the temperate flora to Disko

    Island on the west coast of Greenland; the Eocene equivalent of the Japan

    Current was responsible for the occurrence of cycads, laurels, and Dillenia

    in southeastern Alaska. Distribution of early Cenozoic forests strongly

    supports the conclusion that continents and ocean basins have held essentially

    their present position during at least this latest era of geologic time.

            A question has often arisen in connection with the northern distribution

    of trees during the Eocene: Would trees have been able to maintain themselves

    at high latitudes during the long period of winter darkness? With the

    recently acquired knowledge that our northernmost conifer was not an evergreen

    Sequoia but a deciduous Metasequoia , and with our realization that its

    associates were largely deciduous plants which today range far to the north,

    rather than the [ ?] fanciful figs of earlier opinion, we may answer this

    question in the affirmative. The amount of sunshine received by plants now

    living within the Arctic Circle is wholly adequate for their growth and

    reproduction. And if, as many climatologists have argued, the polar icecaps

    of today are a recent development, we are not forced to include the handicap

    of deeply frozen ground beneath our Eocene forests. Some sort of meridional

    continental drift, always maintaining the relative positions of the northern

    continents and their intervening seaways, might have carried the rocks con–

    taining the fossil record of temperate forests northward from middle to high

    020      |      Vol_V-0330                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    latitudes; but judging from the position of Eocene floras around it, the

    North Pole seems to have maintained a constant position during the past

    seventy million years. Rather than endorsing so complicated and unsupported

    a theory as continental drift, and having in mind the record of the Arcto–

    Tertiary Flora at successively lower latitudes — both in western North

    America and eastern Asia — in rocks of younger age, I find more acceptable

    the alternative of forest migration southward under the compulsion of

    climatic change.



            The records of high latitude forests during the epoch immediately

    preceding our day are scattered and incomplete. I shall consider here the

    only adequate material from North America, which has been studied by Chaney

    and Mason (1936). The collection was made in the frozen alluvial deposits

    near Fairbanks, Alaska, at latitude approximately 65° N.; these deposits

    also contain abundant remains of Pleistocene mammals which are elsewhere

    discussed by Colbert.

            Twenty-seven plants have been recognized, all of which appear to be

    closely related to, or identical with, species now living. There are five

    species of fungi, a puffball ( Bovista ) and four-bracket fungi ( Fomes ,

    Ganoderma ) which are parasitic on woody plants. Eight species of trees and

    shrubs, represented by leaves, fruits, and wood, fall in the following genera:

    Picea , Populus , Salix , Betula ; no differences can be noted between the

    fossil specimens and living species of spruce, aspen, willow, and birch now

    in boreal Alaska. There are fourteen species of herbs which make up the

    largest element of the Fairbanks flora, as is also the case in the modern

    021      |      Vol_V-0331                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    vegetation of today. These species are largely represented by seeds,

    which from their mode of occurrence are interpreted to represent food

    caches of rodents. Among the most abundant herbs are the cotton-sedge

    ( Eriophorum ) and the common sedge ( Carex ), both of which are so character–

    istic of living vegetation at high latitudes. Other herbs are a sandwort

    ( Arenaria ); the moss-campion ( Silene ); a buttercup ( Ranunculus ); a

    member of the mustard family, Draba ; a cinquefoil ( Potentilla ); a member

    of the primrose family, ( Androsace ; A phlox similar to the circumpolar

    species P. sibirica ; and a dandelion, Taraxacum ceratophorum , which is

    also circumpolar in its modern distribution.



            No significant difference can be noted between the Pleistocene

    vegetation of the Fairbanks area and the modern flora or this and other

    regions at high northern latitudes. And while we may regret the gap in

    the record from Eocene to Pleistocene — a gap found not only in Alaska

    but elsewhere in the Arctic — it is fortunate to have this evidence of a

    past so immediate that it almost merges into the present. Of the genera

    known in Eocene floras of the North, only Picea , Populus , Salix , and Betula

    survived into the Pleistocene, and their present-day habit is more nearly

    as shrubs than trees. During the tens of millions of years following the

    Eocene, the Arcto-Tertiary Flora has been gradually shifted southward from

    high latitudes, leaving behind only its hardiest members. In the modern

    forests of northeastern Asia, eastern North America, and to a lesser extent

    in western Europe, we may see the early Cenozoic vegetation of the Arctic,

    and measure the changes which have come about during the era in which we


    Unpaginated      |      Vol_V-0332                                                                                                                  

    Distribution of Tertiary Floras in the Arctic

    022      |      Vol_V-0333                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic


    1. Balzak, S.S., Vasyutin, V.F., and Feigin, G. 1949. Economic geography

    of the U.S.S.R. Macmillan Co.

    2. Berry, Edward. 1922. “A possible explanation of Upper Eocene climates.”

    Proc. Am.Phil.Soc . 61: 1-14.

    3. Chaney, Ralph W. 1930. “A Sequois forest of Tertiary age on St.

    Lawrence Island.” Science 72; 653-654.

    4. ----. 1940. “Tertiary forests and continental history.” Bull .

    Geol.Soc.Am . 51: 469-488.

    5. ----. 1948. “The bearing of the living Metasequois on problems of

    Tertiary paleobotany.” Nat.Acad.Sci . 34 (11): 503-515.

    6. ----. 1949. “The Miocene occurrence of Sequois and related conifers

    in the John Day Basin.” Nat.Acad.Sci . 35 (3): 125-129.

    7. ----. 1949a. “Early Tertiary ecotones in western North America.”

    Nat.Acad.Sci. 35 (7): 356-359.

    8. ----. 1951. “A Revision of Fossil Sequois and Taxodium in western

    North America based on the recent discovery of Metasequoia.”

    Trans.Amer.Phil.Soc . ns 40, Pt. 3:

    9. Chaney, Ralph W. and Mason, H.L. 1936. “A Pleistocene flora from

    Fairbanks, Alaska.” Amer.Mus.Novitates 887: 1-17.

    10. Chu, Kwei-ling and Cooper, William S. 1950. “An ecological reconnaissance

    in the native home of Metasequois glyptostroboides.” Ecology 31:


    11. Durham, J. Wyatt. 1950. “Cenozoic marine climates of the Pacific Coast.”

    U.S.Geol.Soc.Am.Bull. 61: 1243-1264.

    12. Goeppert, R. 1867. “Ueber die Tertiarflora der Polarländer.”

    Jahresbericht d. Sches.Gesellechaft 44: 50.

    13. Heer, Oswald. 1868. Flora Fossilis Arctica , 1. Pt.1. Taimyr: 41.

    14. ----. 1868a. Flora Fossilis Arctica , 1. Pt.2. Miocene Flora von

    Nordgronland: 86-130.

    15. ----. 1868b. Flora Fossilis Arctica , 1. Pt. 2. Bathurst-Insel:


    16. ----. 1868c. Flora Fossilis Arctica , 1. Pt. 2. Miocene Pflanzen

    des Bankslandes: 134-135.

    023      |      Vol_V-0334                                                                                                                  
    EA-PS. Chaney: Arctic Forests of the Cenozoic

    17. ----. 1868d. Flora Fossilis Arctica , 1. Pt. 2. Miocene Flanzen

    vom Mackenzie: 135-139.

    18. ----. 1868e. Flora Fossilis Arctica , 1. Pt. 2. Miocene Flora

    von Island: 139-155.

    19. ----. 1868f. Flora Fossilis Arctica , 1. Pt. 2. Miocene Flora

    von Spitzbergen: 155-161.

    20. ----. 1871. Flora Fossilis Arctica , 2. Pt. 2. Flora fossilis

    Alaskana: 1-41.

    21. ----. 1871a. Flora Fossilis Arctica , 2. Pt. 3. Der Miocene

    Flora und Fauna Spitzbergens: 1 - 98.

    22. ----. 1871b. Flora Fossilis Arctica , 2. Pt. 4. Contributions to

    the fossil flora of North-Greenland: 445-488.

    23. ----. 1874. Flora Fossilis Arctica , 3. Pt. 3. Nachträge zur

    miocenen Flora Grőnlands: 1-29.

    24. ----. 1876. Flora Fossilis Arctica , 4. Pt. 1. Beiträge zur

    Fossilen Flora Spitzbergens: 1-93.

    25. ----. 1878. Flora Fossilis Arctica , 5. Pt. 1. Die miocene Flora

    des Grinnell-Landes: 1-38.

    26. ----. 1878a. Flora Fossilis Arctica , 5. Pt. 2. Tertiare Pflanzen

    vom Tschirimyi-Felsen an der Lena. Tschirimyi: 30-36.

    27. ----. 1880. Flora Fossilis Arctica , 6. Pt. 2. Nachträge zur

    fossilen Flora Grőnlands: 1-17.

    28. ----. 1880a. Flora Fossilis Arctica, 6. Pt. 3. Miocenen Flora

    von Nord-Canada: 1-17.

    29. ----. 1883. Flora Fossilis Arctica , 7. Pt. 2. Die tertiäre

    Flora von Grőnland: 47-142.

    30. Hollick, Arthur. 1936. “The Tertiary floras of Alaska.”

    U.S.Geol.Surv.Prof.Paper 182: 1-175.

    31. Hu, Hsen-Hsu. 1946. “Notes on a Paleocene species of Metasequoia

    in China.” Bull.Geol.Soc. of China 26: 105-107.

    32. Hu, Hsen-Hsu and Chaney, Ralph W. 1940. A Miocene flora from Shan g tung

    Province, China. Carnegie Inst. Wash. 507.

    33. Hu, Hsen-Hsu and Cheng, Wan-Chun. 1948. “On the new Family

    Metasequoiaceae and on Metasequois glyptostroboides. a living

    species of the Genus Metasequois found in Szechuan and Hupeh.”

    Bull.Fan Mem.Inst. of Biol . 1 (2): 153-161.

    024      |      Vol_V-0335                                                                                                                  
    EA-PS. Chaney: Arctic [ ?] Forests of the Cenozoic

    34. Kryshtofovich, A.N. 1929. “Evolution of the Tertiary flora in Asia.”

    New Phytologist 28 (4): 303-312.

    35. ----. 1934. “The Tertiary flora of the Korf Gulf, Kamchatka.”

    Trans.Far East Geol. and Prospecting Trust 62: 1-28.

    36. ----. Undated. “New Contributions to the Tertiary and Cretaceous

    Floras of the Aral-Caspian Province and its Correlation to

    the floras of Northern Asia.” Ser.4, 2: 244.

    37. Miki, S. 1941. “On the change of flora in Eastern Asia since

    Tertiary Period (I). The clay or lignite beds flora in Japan

    with special reference to the Pinus trifolia beds in Central

    Hondo.” Jap.Jour.Bot . 11: 237-303.

    38. Munns, E.N. 1938. The distribution of important forest trees of the

    United States . U.S.Dept.Agric. 287.

    39. Nathorst, A.G. 1888. “Zur fossilen Flora Japans. Palaeontologische

    Abhandlungen von Dames und Kayser ” 4, Heft 3: 52.

    40. ----. 1915. “Tertiare Pflanzenreste aus Ellesmere-Land.” Report of

    the Second Norwegian Arctic Expedition in the “Fram” 1898-1902 .

    35: 1-16.

    41. Palibin, E.B. 1905. “Plant remains from the Commander Islands.”

    Western Imp.Russ. Mineralogical Soc . Ser.2, Pt.42: 28.

    42. Schmalhausen, J. 1890. “Beschreibung der tertiaren Pflanzen von

    New-Siberien.” Mem.Acad.Imp.Sci.St. Petersburg 37: 10-22.

    43. Schmidt, F.B. 1900. “New material from the shores of Okotsk Sea.”

    Western Imp.Russ.Mineralogical Soc. Ser.2, Pt.28: 50-51.

    44. Zon, Raphael and Sparhawk, William. 1923. Forest Resources of the

    World . McGraw-Hill Book Co.


    Ralph W. Chaney

    Pleistocene and Recent Paleobotany (Excluding Greenland)

    Unpaginated      |      Vol_V-0336                                                                                                                  
    EA-Plant Sciences

    (G. Erdtman)





    Fossil-Bearing Deposits 2
    Interpretation of Fossils 4
    Dating of Fossiliferous Deposits 6
    History of Climate and Vegetation 6
    Future Work and Prospects 8
    Bibliography 10

    001      |      Vol_V-0337                                                                                                                  
    EA-Plant Sciences

    (G. Erdtman)




            The present provides the key to the past, the truth of this cannot

    be denied. Nevertheless, paleobotanists have as a rule not paid much

    attention to fossil plant remains and potential fossils in Pleistocene

    and Recent deposits. Stumps and stems of ferns and conifers — hundreds

    of millions of years old — have been treated with respect, whereas

    fossils buried in Quaternary strata for only five to fifty thousand years

    have frequently been neglected. Paleobotanically speaking, the latter

    have not yet come of age. However, to make the record complete, that is,

    to trace the history of plants from the present day to remote ages,

    botanists should first study the living plants, then actuopaleontology

    (i.e., the transformation of living substance into fossils), and finally

    paleontology itself, beginning with the most recent fossils proper. Until

    this had been accomplished, more or less wide gaps will remain between our

    knowledge of Pleistocene and Recent fossils, gathered by plant geographers,

    Quaternary geologists, and others, and that of older fossils supplied by


            Speaking of gaps, it should also be pointed out that our paleobotanical

    002      |      Vol_V-0338                                                                                                                  
    EA-PS. Erdtman: Pleistocene and Recent Paleobotany

    knowledge is derived so far chiefly from the study of megafossils (i.e.,

    more or less large fossils: tree trunks, leaves, fruits, seeds, etc.)

    Proper attention should, however, also be paid to the study of microfossils,

    such as pollen grains and spores. Recognition of the importance of “paleo–

    lapynology” (palynology: pollen and spore science; from the Greek verb

    palyno, to spread) as an auxiliary paleobotanical science is gradually

    increasing. The ideal development of paleobotany would be to secure, as

    far as possible, a continuous record of plant microfossils as well as

    megafossils back through the ages.

            The arctic region is still in many respects, including Pleistocene and

    Recent paleobotany, a terra incognita . This article can, therefore, present

    only a few facts and suggestions about a vast area where extreme conditions

    tend to make investigations difficult, and where any results may be obtained

    are particularly interesting.


    Fossil-Bearing Deposits

            The Pleistocene and Recent fossils (or subfossils) of the Arctic are

    preserved in various ways: in ice, frozen soil, peats, or sediments of

    different types. These media are not always stable: for example, peat and

    sediment may be broken up and destroyed; and if the ice melts, imprisoned

    “cryofossils” are released.

            Investigations in Switzerland (64; 65) have shown that glacier ice

    contains pollen grains and spores in amounts sufficient for analyses. This

    opens a new approach to the study of glacial movements and the rate of firn

    and ice formation. Investigations of this kind have, however, not yet been

    made in the Arctic.

            In temperate regions, peat deposits usually form the chief source of

    003      |      Vol_V-0339                                                                                                                  
    EA-PS. Erdtman: Pleistocene and Recent Paleobotany

    Pleistocene and Recent fossils. By investigating these natural archives — their

    stratification, and included stumps, seeds, and microfossils — detailed pictures

    may be obtained not only of vegetational history but also of climatic changes.

    In the relatively mild and wet northwestern parts of Europe, peat accumulations

    attain locally a thickness of 30 feet and span a period of 1 0,0 00 or more years.

            The climate of the Arctic does not favor peat formation, and true peat of

    considerable thickness is rarely found in [ ?] arctic regions. It is reported from

    Alaska, however, that peat on the tundra reaches a thickness of 2 to 150 feet,

    and may even attain 300 feet. This depth has, according to Russell (56), been

    assigned by several observers to the peat of the subarctic tundra where it is

    exposed on a sea cliff in Eschscholtz Bay, at the head of Kotzebue Sound. This

    interesting locality has received more attention than any similar portion of the

    shore of Alaska, owing to the fact that the ice is well exposed and the surface

    layer of human is rich in mammalian remains. The peat is still forming, [ ?]

    although the material lying below is frozen at a depth of only 8 to 14 inches.

    In the unforested lands of northern and northwestern Canada, moss peat ( Sphagnum

    bog) is said to be little developed (63). Concerning peats and boggy strata in

    the Canadian Eastern Arctic, right up to northern Baffin Island, see Polunin

    (52) and papers quoted therein. On Richards Island, in the Canadian Western

    Arctic, 60 or 70 miles north of the present limit of trees, well preserved roots

    and stumps of a former spruce forest are found in situ , now covered with a peat

    deposit many feet thick. Potamogeton epiphydrus var. nuttallii , discovered in the

    peat deposits of Pingorssera juk, is not now anywhere found in the Northwest

    Territories (53a).

            Conditions in Greenland are described by Iversen in Pleistocene and Recent

    Paleobotany of Greenland. It will only be added here that peat has been found by

    Backlund (8) in the northeastern part of that huge island, and that this was one

    of the nor h t hernmost finds or true peat so far made.

    004      |      Vol_V-0340                                                                                                                  
    EA-PS. Erdtman: Pleistocene and Recent Paleobotany

            According to Nathorst (44), peaty deposits are not rare in Spitsberge.

    A deposit of Amblystegium peat, six feet deep, occurs in the Dape Thordsen

    Peninsula, and Craig (16) mentions peat thicknesses of up to two or three

    feet at several localities.

            In the tundra peat in the Kanin Peninsula, whose maximum thickness is

    18 feet according to Jacobi (27), finds of tree trunks up to 20 feet in

    length have been made (55). Part of Kolguev Island is covered by tundra

    peat (62), and quagmires exist on the South Island of Novaya Zemla (cf.

    Holm, 24) where Lid (40) even speaks of a Sphagnum even speaks of a Sphagnum

    big. Here, as in Spitsbergen, Sphagnum squarrosum is the commonest species.

    This species also occurs in a “dead” bog near Krestovaia Bay on the North

    Island, in which peat formation has ceased and the peat itself is a sign

    of conditions more favorable than those of the present day (37). The

    scanty pollen flora of [ ?] Carex-Hypnum peats (3 to 4 feet deep)

    on the west coast of the South Island has been studied by Kudrjaschos (37).

    The finds of stray pollen of lime ( Tilia ) are particularly remarkable.

            Further information on peat in Arctic Russia and Siber f i a is given by

    Alabyshev, Anufriev, Bronsov, Dokturovski, Igoshin, N. and S. Katz,

    Lavrova, and others.


    Interpretation of Fossils

            Some fossils are autochthonous, i.e., remnants of plants living on

    or near the spot; others are allochthonous, i.e., carried by different agencies,

    usually wind or water, from more or less distant places. Allochthonous

    specimens may also include redeposited fossils from older, broken-down

    strata. Much confusion may arise if the allochthonous and autochthonous

    components of a fossil record cannot be readily differentiated.

    005      |      Vol_V-0341                                                                                                                  
    EA-PS. Erdtman: Pleistocene and Recent Paleobotany

            Foremost among allochthonous megafossils are logs and other woody

    debris carried by the great rivers to the Arctic Sea, distributed by

    oceanic currents, thrown ashore, and finally embedded in sandy, clayey,

    or peaty deposits. They also include seeds of the famous sea bean

    ( Entad [ ?] gigas ), a product of the West Indies that is occasionally found

    floating ashore in Ireland, Norway, and even Spitsbergen. Long-distance

    transportation of insects is reported by Elton (19); in the summer of 1924

    vast swarms of hover flies ( Syrphus ribesii ) and spruce aphids ( Dilachnus

    [ ?] piceae ) were blown from northern Europe to the icecap of North

    East Land, Spitsbergen — a distance of over 800 miles. They were living

    when they arrived, but perished later in a blizzard. Transportations in

    reverse direction occur occasionally; animals and plant remains may thus

    be carried by icebergs or other means from Spitsbergen to the northern

    coasts of Europe.

            Potential microfossils (such as pollen grains and spores) and small

    particles of apt kind are not to be spread in greater quantities and over

    longer distances than larger bodies. Ash from an eruption in Iceland

    reached Finland (Helskngki) after 51 hours (57), and at the time this

    article was being written (in Stockho [ ?] l m, October 1950), the sun occasionally

    assumed a bluish shade from fine dust suspended at high altitudes in the

    air. Volcanic eruptions in eastern Asia and forest fires in western

    Canada are believed to have been responsible for this dust.

            Pollen grains and spores were trapped by Charles Lindbergh during

    flights over the inland ice of Greenland (cf. Meier, 43), and similar

    experiments have been made in Arctic Canada and the Polar Basin by Nicholas

    Polunin and worked out with the assistance of his colleagues (53).

    006      |      Vol_V-0342                                                                                                                  
    EA-PS. Erdtman: Pleistocene and Recent Paleobotany

    Some years ago the pollen grains in the atmosphere over the Atlantic

    Ocean were investigated during a journey from Gőteburg to New York (20).

    Pollen grains and spores were trapped all the way, even in midocean, and

    200 miles off Newfoundland considerable quantities of alder pollen grains

    were caught, having been carried there from Newfoundland by strong north–

    easterly winds. The peat in Greenland contains small amounts of allochthonous

    coniferous pollen grains from the continent of North America.


    Dating of Fossiliferous Deposits

            G. De Geer’s geochronological method, based on the study of sediments

    with annual banding, has been instrumental in calculating the exact duration

    of late Quaternary times (cf. De Geer 17). The same method will probably

    prove useful in some outskirts of the Arctic, e.g., in Alaska (cf. Russell,

    56). If absolute geochronology cannot be applied, the relative age of a

    fossiliferous deposit can be ascertained by other methods. Among these is

    the study of the deposits’ relation to the strand lines, which are widely

    spread in different parts of the Arctic. Pioneer work in this difficult

    field has been done by Tanner (61). Archaeological finds in or near the

    deposits may also be instrumental in dating (14; 68).


    History of Climate and Vegetation

            In the arctic region practically no investigation of these aspects

    have been made bymodern methods except by Iversen (see Pleistocene and

    Recent: Greenland). Here, therefore, only a brief summary of some results

    of research during the last hundred years (1850-1950) will be given.

    Unfortunately, valuable information has often been published in more or

    less local journals and periodicals, difficult of access to the general

    007      |      Vol_V-0343                                                                                                                  
    EA-PS. Erdtman: Pleistocene and Recent Paleobotany

    reader, and much of it is in Russian without summaries in other languages.

            Climatic changes and their influence on the vegetation have been

    dealt with by Andersson, Backlund, Heer, Nathorst, Neustadt and Tulina,

    Obruchev, Subkov, Sukachev, Tyrrell, and others. Permanently frozen soils

    and their relation to local vegetation have been described by von Baer,

    Johnston, Malchenko, Kayser, Krueger, Nikiforoff, and others. According

    to the findings of these authors, it can be safely concluded that the

    arctic region during Quaternary times witnessed one or several interglacial

    periods with milder c e l imatic conditions than the present ones. It has,

    furthermore, been established that during postglacial times the climate

    was for a period warmer than now: thus the mean temperature during the

    season of growth in Spitsbergen was probably 2.5 - 3°C. higher than at

    present (3).

            Remains of the seaweed Pelvetia canaliculata occur in the Mytillus

    layers at Advent Bay, Spitsbergen (23); the layers are probably inter–

    glacial. A small leaf-fragment of, apparently, Dryas integrifolia has

    been found in the same beds. Neither Pelvetia canaliculata nor Dryas

    integrifolia occurs on Spitsbergen today. Similarly interglacial are the

    remains of Alnus fruticosa and Betula alba (occurring together with remains

    of mammoth, rhinoceros, horse, and saiga antelope) in the New Siberian

    Islands. In the Taimyr Peninsula fossil wood, especially of Larix , is

    frequent up to latitude 74° 30' N. (7). The modern tree line lies in most places

    near to parallel. The wood, which consists partly of large logs, rests

    on permanently frozen soil and is locally overlain by ground ice. It may

    be of interglacial age.

            In Quaternary beds in the Seward Peninsula, Alaska, in regions now

    008      |      Vol_V-0344                                                                                                                  
    EA-PS. Erdtman: Pleistocene and Recent Paleobotany

    treeless, large trunks of trees have been found together with remains

    of mammoth, horse, and other mammals (15; 41; 54).

            The presence of Salix herbacea hybrids in Novaya Zemlya is one of

    the many botanical indications of milder climatic conditions in post–

    glacial times; pure Salix herbacea does not now grow in this sector of

    the Arc g t ic north of Vaigach Island (37). Still stronger arguments in

    favor of an earlier postglacial climatic optimum have been provided by

    zoologists (28; 35; 47). Forest fires and human influence have contributed

    to widening the area of the arctic tundra, but cannot alone, as argued by

    Wigge (67), be responsible for the shrinking and withdrawal of the northern–

    most forests.


    Future Work and Prospects

            Paleontological researches in the critical zone of tension between

    tundra and forest are likely to yield results of outstanding interest.

    Studies like those of Aario and others in northern Finland may serve as

    examples. The composition of the arctic tundra vegetation should be

    compared with its “pollen and seed pictures,” i.e., the way in which the

    actual vegetation is reflected by the seeds and pollen grains in living

    (still growing) strata of fossiliferous deposits should be studied. Near

    Bőteborg, about 8,000 pollen grains per year settle on one square millimeter

    of the sea bottom, about 45 feet below the ordinary shore line. How many

    grains are actually settling in the arctic waters or muskegs, and of

    what kind are they? The composition of the present-day “pollen rains”

    can to some extent be determined by pollen analyses of powdered lichens.

    The lichens often contain large amounts of pollen grains and provide

    009      |      Vol_V-0345                                                                                                                  
    EA-PS. Erdtman: Pleistocene and Recent Paleobotany

    “mean values” for a score of years. Similar investigations, if made in

    Canada and Siberia, would provide keys for unlocking some of the problems

    connected with the history of climate and vegetation in the Arctic.

            Research in the tension zones and farther north, in the true tundra,

    would also contribute to the interpretation of some fossil records of

    arctic or quasi-arctic conditions in areas of former glaciation. How does

    a vegetation invading the soil laid bare by a withdrawing ice sheet compare

    with present-day arctic vegetation? And to what extent can be composition

    of this vegetation be explained on a purely ecological nonclimatic basis?

            At the time of the disappearance of the last remnants of “dead” ice

    in northern Scandinavia, the climate was probably more favorable than that

    of the present day. The flora invading the virgin soils comprised sun-loving

    “pioneers and vagabonds” ( Hippophaë , Artemisia and other Compositae, etc.),

    a colorful vanguard, later shaded to death and exterminated by forests of

    birch, pine, alder, and some admixture of hazel, oak, lime, elm, and ash.

    There are somd points in common between the pioneer flora and that

    occurring in some places in or near the Arctic, e.g., in Kanin Peninsula.

    Here Matricaria and Sonchus grow in profusion — note also the finding by

    Jonas (30) of 90-100% composite pollen grains in “subarctic” strata

    in German. Helianthemum oelandicum , a late-glacial member of the flora

    of Sweden and Denmark, is also said to occur in Kanin (51).

            The investi v g ations of the Pleistocene and Recent deposits in the

    Arctic should proceed step by step, beginning in the southern tension

    zones. In this way they would be linked upwith those in the subarctic

    forest areas and a strong, critical contact would be upheld with various

    well-established data – geochronological, phytogeographical, climatological,

    and archeological.

    010      |      Vol_V-0346                                                                                                                  
    EA-PS. Erdtman: Paleobotany: Pleistocene and Recent


    1. Aario, L. “Über die Wald- und Klimaentwicklung an der lappländischen

    Eismeerkűsten in Petsamo,” Societas Zool. –BotFenn.Van.

    Ann.Bot . vol.10, no.1, 1943.

    2. Alabyshev, V.V. “Über einene Fund von Eichenpollen in Mooren von

    Zentral- Jakutien,” Trav .Comm.Quat.Acad., no.2, pp.185-213.

    Leningrad, 1932.

    3. Anderson, G. “The climate of Sweden in the Late-Quaternary period,”

    Sweden. Geol.Surv. ser.C, no.218, 1909.

    4. ----. “Die jetzige und fossils Quartärflora Spitsbergens als Zeugnis

    von Klimaänderungen,” Veränderungen des Klimas, etc. Stockholm,


    5. Antevs, E. The Last Glaciation . -Amer.Geogr.Soc. Res.Ser . no.17, 1928.

    6. Anufriev, G.J. “Die Moore der Halbinsel Kola,” Arb.der bodenkundl .–

    botan. Abteil. d. nord.wissensch. -gewerbl . Exp. St.Petersburg,


    7. Backlund, H. “Arktisk forskning vid Siberiens nordspets,” Ymer ,

    vol.45, pp.495-508, 1925.

    8. ----. “Über die La v g erungsbedingungen eines Torffundes in NO- Grőnland,”

    Medd.Grønland vol.87, no.1, 1931.

    9. von Baer, K.E. “On the ground ice or frozen soil of Siberia,” Roy.Geogr.

    Soc. J . vol.8, 1838.

    10. Blagowestschensky, A. “Formation of forests in the Glacial region of

    European USSR in relation with the climatic fluctuations of

    the Quaternary,” Akad.Nauk.Inst.Geogr. Trudy , 1946, pp.267-303.

    11. Bronsov, A.J. Die Hochmoore des Narymgebiotes , Naut. -issl.Torf Inst.,

    Trudy , 3, Moscow, 1930.

    12. Brooks, C.E.P. The Evolution of Climate . London, 1922.

    13. Chamberlin, T.C. “Significant amelioration of present arctic climates,”

    J.Geol . vol.31, pp.376-406, 1923.

    14. Chernov, G.A. “Archäologische Funde im Mittelteil der Bolschesemlja–

    Tundra,” Quartär-Komm. Wiss.Akad. USSR, Arb ., 7, pp.55-122, 1948.

    15. Collier, A.J. “Geography and Geology.” in “The gold placers of parts of

    Seward Peninsula, Alaska,” U.S.Geol.Surv. Bull . no.328, 1908.

    011      |      Vol_V-0347                                                                                                                  
    EA-PS. Erdtman: Paleobotany: Pleistocene and Recent

    16. Craig, R.M. “Outline of the geology of Prince Charles Foreland,

    Spitsbergen,” Edinb.Geol.Soc. Trans [ ?] vol.10, pp.276-88,


    17. De Geer, G. “Geochronologia Suecica,” Svenska Vetens Kapsakad.

    Handl. 3, ser. 18 (6). Stockholm, 1840.

    18. Dokturovski, V. “Die Moore Osteuropas und Nordasians,” K.von Bülow,

    Handbuch der Moorkunde, vol.4, 1938.

    19. Elton, C.S. The dispersal of insects to Spitsbergen . Roy.Ent.Soc.

    Lond. Trans . pp.289-99, 1925.

    20. Erdtman, G. An introduction to pollen analysis . F.Verdoorn, New Ser.

    Plant Sci.Books, vol.XII.) Waltham, Mass., 1943.

    21. Goworuchin, W.S. “Rastitelnost basseina reki Ylytscha (sev. Ural).”

    (The vegetation in the district of the Ylytsch river,

    North Ural). Obstsch.isutsch.Urala, Sib. i i daln. Vostoka , 1.

    Moscow, 1929.

    22. Grigoriev, A. “Die Typen des Tundra-Mikroreliefs von Polareurasien,

    ihrs geographische Verbreitung und Genesis,” Geogr. Zeitschr .


    23. Heer, O. “Die miocene Flora und Fauna Spitzbergens. Mit eines Anhang űber

    die diluvialen Ablagerungen Spitsbergens,” Svenska Vetens

    Kapsakad. Handl . vol.8, no.7, 1870.

    24. Holm, T. “Novaia-Zemlia s Vegetation,” Djimphna-Togtets zool. -bot .

    Udbytte . Copenhagen, 1885.

    25. Horn, G., and Orvin, A.K. “Geology of Bear Island,” Norsk Polarinstitutt.

    SKP . no.15, 1928.

    26. Igosh e i n, K.N. “On poor forest and frozen swamps near Iwdelski, Transuralia.”

    (Russian.) Sov.BotJourn ., 34 (5), pp.493-506, 1949.

    27. Jacobi, A. “Die Tundra,” Geogr.Zeitschr . vol.25, 1919.

    28. Jensen, A.S., and Harder, P. “Post-glacial changes of climate in

    arctic regions as revealed by investigations on marine

    deposits,” Veränderungen des Klimas, etc . Stockholm, 1910.

    29. Johnston, W.A. “Frozen ground in the glaciated parts of northern Canada,”

    Roy.Soc.Can. Proc . 1930, Sec.4.

    30. Jonas, F. “Zur Entstehung und Ausbreitung der spätglazialen

    Heidevegetation. Ein Beitrag zur Frage der Schwarzsand- und

    Schwarzerdeentstehung in Mitteleuropa,” Beihefte 2.

    Bot.Centralbl. , vol.59, B, pp.89-112, 1939.

    012      |      Vol_V-0348                                                                                                                  
    EA-PS. Erdtman: Paleobotany: Pleistocene and Recent

    31. Katz, N. “Über die Typen der Moore der westsiberischen Niederung und

    ihre geographische Zona r t ion,” Bericht Dtsch. Bot.Ges. ,

    vol.48, pp.13-25, 1930.

    32. ----, and Katz, S. “History of swamp vegetation in North Siberia as

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    35. Knipovich, N. “Zur Kenntniss der geologischen Geschichte der Fauna des

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    Semenoved, Glav.BotSada, Zapiski , ser.2, vol.38, 1900.

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    37. Kudriashov, W. “Torfmoore der Beluschij Halbinsel (Nowaja Zemlja),”

    Plovuchii Morsk.Nauch.Inst., Moscow. Trudy vol.12, 1925.

    38. Lavrova, M. “Contributions to the exploration of the Quaternary

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    Akad.Nauk.Inst.Geol. [ ?] Tra n v . , 3, 1933.

    39. ----. “Zur Geologie der Onega-Halbinsel im Weissen Meer,” Akad.Nauk.

    Mus.Geol., Trav ., 8, 1930.

    40. Lid, J. “Sphagna from Novaya Zemlya,” Rep.Sci.Res.Norw.Exp. to N.Z. 1921 ,

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    41. Maddren, A.G. “Smithsonian exploration in Alaska in 1904 in search of

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    Matt.Comm. e é t.R e é p.aut.sov.soc.Jakoute , no.11, 1928.

    43. Meier, F.C. “Microorganisms in the atmosphere of arctic regions,”

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    44. Nathorst, A.G. “Beiträge zur Geolgie der Bären-Insel, Spitzbergens

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    flora and of the Anadyr basin,” Leningrad, Arkticheskii

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    46. Nikiforov, C. “The perpetually frozen subsoil of Siberia,” [ ?] .

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    47. Nordmann, V. “Anomia squamula L. som Kvartaer-Fossil paa Spitzbergen,”

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    49. Penck, A. “Paläoklimatologie,” Geogr.Zeitschr . vol.38, 1932.

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    54. Quackenbush, L.S. “Notes on Alaska mammoth expeditions of 1907 and 1908,”

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    G. Erdtman

    Pleistocene and Recent Paleobotany of Greenland

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    EA-PS. Iversen: Paleobotany of Greenland



            Fig. 1. Kingak (1620 m.) in the Godthaab Fjord area. During the glacial

    ages, this mountain projected as a nunatak above the inland ice, and has,

    therefore, been modelled by local glaciers (alpine type). Refuge area for

    hardy arctic plants during glacial time. *

            Fig. 2. Transport of one of the pontoons to a lake in the Tungmeralik valley.

    Powerful planar erosion caused by the friction of the inland ice has resulted

    in the dome-shaped mountains. In the foreground a birch-lichen mat is seen. *

            Fig. 3. Scrub of alder (dark bushes) and willows on the bank of a small river.

    Majaragssuit, interior of Godthaab Fjord. *

            Fig. 4. Luxuriant mat of grasses and herbs adjacent to the ruins of a small

    Norse farmstead. Tufts of Poa glauca and inflorescences of Campanula rotundifolia

    are conspicuous. Archangelica officinalis is seen to the left. In the background

    is Betula nana scrub. *

            Fig. 5. Composite pollen diagram from a lake 100 meters above recent sea-level.

    The lowermost analyses are from samples deposited in brackish water, as indicated

    by their diatom flora. Each analysis gives the relative frequency of the various

    species. The basis of calculation is the total of all pollen (excepting that of

    water plants. Before calculation, the pollen number of Betula and Alnus are

    reduced to 1/4, that of Juniperus to 1/2, while the number is doubled in the case

    of Ericaceae. The figures on the extreme left indicate the place in the diagram

    where 3 different lakes were isolated from the fjord; the height above recent

    sea-level of these lakes is 100 meters, 59 meters, and 8 meters, respectively.

    As to the zones (I-V)), see the text. — Page 14

            Fig. 6. Pollen diagram from a lake adjacent to the Norse farmstead at Kapisilik;

    of. fig. 5. The diagram comprises only the zones III-V. Zone V is subdivided in

    a, b, c; b corresponds to the period of Norse colonization, i.e. from 1000 to

    about 1400 A.D. The great thickness of the deposit from this period is due to

    strong inflow of sand and charcoal. The frequency of microscopie charcoal

    fragments on the slides is indicated on the extreme right ! before the arrival

    of the Vikings, charcoal is found only exceptionally. Macrobiotus, i.e. eggs of

    Tartigrades, indicates the occurrence of moss carpets ( Aulacomnium spp.,

    Sphagnum spp.), c.f. fig. 7. — Page 14

            Fig. 7. Profile from a small bog adjacent to a Norse farmstead at Ujaragssuit.

    1 moss-peat; 2 sandy mud; 3 pure sand; 4 sandy gravel; 5 layer of charcoal,

    washed down when the Icelandic Vikings arrived and burnt off the scrub. Wood

    chips were found in the same layer. Beneath this level charcoal was absent;

    above, scattered pieces of charcoal was found until 6, the uppermost charcoal

    pieces; 7 pupae of Agrotis oculta . In the stratum of charcoal (5), pollen

    grains of grasses and herbs suddenly become dominant. In the layer of pupae (7),

    the pollen grains of herbs again become less frequent, while those of willow

    increase sharply. Simulatenously the bog becomes covered with mosses, either

    owing to the termination of colonization, or because of a climatic change to

    dryer conditions. — Page 14

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    EA-PS. Iversen: Paleobotany of Greenland


    List of figures

            Fig. 8. Sketch map drawn on the basis of information in Finn Salomonsen’s

    work (The Birds of Greenland 1950). Some geese fly directly from Scotland to

    South Greenland and vice versa (occasionally a direct connection between

    Scotland-Ireland and North America may occur, exceptionally the migrants may

    be diverted from their customary course). — Page 15

            Fig. 9. Sisyrhinchium montanum on a south-facing slope adjacent to the ruins

    of a Norse farmstead near Kapisilik. Nearest locality outside Greenland is more

    than 1000 km. to the [ ?] -SW in Labrador. Presumably it was accidentally introduced

    from the St. Lawrence Bay region during the Norse expeditions from Greenland to

    America. It has been found at three ancient Nose farmsteads in the interior

    of Bodthaab Fjord. Further, one locality is known from the little explored

    Sdr. Strőmfjord regions, where so far no ruins of Norse farmsteads have been

    found. The possibility that Sisyrinchium has immigrated with birds during the

    post-glacial warm period cannot be excluded. *

    * Because of the high price of reproduction, these photographs are being

    retained at The Stefansson Library.

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    EA-Plant Sciences

    (Johs. Iversen)



            The favorable climate in Greenland during the Tertiary period terminated

    with a sharp decline in temperature. Snow and ice accumulated and the inland

    ice came into existence. The luxuriant and rich Tertiary flora was followed

    by the hardy and relatively depauperate arctic plants.

            The deterioration of the climate culminated during the glacial ages; we

    must assume that they brought about great advances of the ice even in Greenland.

    We know, however, nothing about the varying extent of the inland ice during

    the Pleistocene period, as the last advance seems to have reached farthest

    of all.

            Each glacial period, no doubt, decimated the flora of Greenland. Between

    these periods of bitter cold, i.e., in the “interglacial” periods, the improve–

    ment in climatic conditions gave rise to a recrudescense of the flora. The

    isolated position of Greenland — wide waters divide southern Greenland from

    the North American and European continents — is, however, a serious obstacle

    to the immigration of plants. Hence, the question of the origin of the flora

    of Greenland arises: did the flora, or any part of it, survive the glaciations

    on ice-free refuges in Greenland, or must we assume that it was totally destroyed

    in each successive glaciation?

            The problem was first presented by the well-known Danish botanist Eugen

    Warming, who in 1889 asserted that a considerable portion of the Greenland

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    EA-PS. Iversen: Paleobotany of Greenland

    flora might have survived at any rate the last glaciation on ice-free moun–

    tain peaks, the so-called “nunataks” (cf. fig. 1). Warming’s assertion

    became the starting point of a lively scientific debate among botanists,

    and opinions varied (and still vary) greatly — cf. a review of the initial

    part of the discussion in Ostenfeld’s paper, also the recent contributions

    by Gelting (1932, 1941), Bőcher (1938, 1948), and Dahl (1949).

            The discussion has hitherto been based exclusively on the theoretical

    evaluation of the present distribution of the plants in question; in this

    contribution, however, the problem will be dealt with on the basis of some

    recent pollen analytical material.

            No interglacial deposits are known from Greenland. The inland ice

    seems to have scoured them off totally during the last glacial age. On the

    other hand small bits of concretions, often with fossilized marine fishes,

    can be found high in the mountains, whither one can be sure that they have

    been transported by glaciers; they must, therefore, be of interglacial age.

    Fortunately, these concretions have been found to contain pollen grains that

    are well preserved and present in ample number.

            A pollen analysis from a small concretion found at the head of Godthaab

    Fjord gives information as to the vegetation in this region during inter–

    glacial time. In broad features we find the same subarctic vegetation type

    which characterizes the postglacial warm period (cf. later). Scrub of birch,

    alder, willow, and juniper were frequent; also various grasses, herbs, ferns,

    and Ericaceae. On the beach grew chenopods and Plantago maritima . There is,

    however, one striking difference: The presence of Picea , which is well repre–

    sented in the pollen analysis. No conifers, except juniper, are known to have

    lived in Greenland since the last ice age. The same applies to Filipendula ,

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    EA-PS. Iversen: Paleobotany of Greenland

    a herb demonstrated in the pollen analysis. These facts are an indication

    that in Greenland, as in Europe, the interglacial flora was richer than

    the postglacial one.

            The development of the vegetation in postglacial time has been studied

    by pollen analysis of the deposits in lakes and bogs of the interior of

    Godthaab Fjord. The main investigation was carried out in Tungmeralik

    (lat. 64°15′ to 64°25′ N, long. 51°50′ W.), one of the largest and most

    sheltered valleys in southern Greenland, which contains a series of lakes

    at varying altitudes. Numerous ruins of farmsteads from [ ?] the ancient

    Viking colonization are found in the valley. The material was [ ?] gathered

    during 1937 in a number of these lakes by borings from pontoons (fig. 2),

    In addition, some bogs of other parts of the inland region of the Godthaab

    Fjord district were investigated.

            The vegetation in the territory studied is relatively luxuriant, though

    somewhat impeded by drought. Following the water-courses and in other favor–

    able and sheltered places we find willow scrub (fig. 3) interspersed with

    Alnus crispa . Predominant, however, is Betula nana , forming heaths or low

    scrub, associated with Ericaceae or low willows and, on southerly slopes,

    also with Juniperus. Ledum groenlandicum forms a luxuriant low scrub on

    westerly slopes, while Ledum decumbens is generally found in exposed and

    less favorable places. Vaccinium uliginosum and Empetrum hermaphroditum

    are very common, especially in the montane zone, where they form large heaths.

    Vast areas are covered with lichen health, with scattered dwarf-shrubs or

    grasses (cf. fig. 2). Luxuriant mats of grasses and herbs are found at the

    old farmsteads. Even now, some 600 years after the settlements were aban–

    doned, the vegetation still shows the results of the fertilization of those

    days (cf. fig. 4).

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    EA-PS. Iversen: Paleobotany of Greenland

            Long-distance transport of pollen, which in most arctic regions is an

    extremely grave source of error in pollen analysis, is in Greenland of little

    importance. This is, of course, because of its isolated position. All pollen

    grains of conifers, except juniper, must have come across the sea; but this

    long-distance conifer pollen (principally Picea pollen) amounts to approxi–

    mately 1% only of the total pollen count, which is an extraordinarily low

    figure. The pollen diagrams, therefore, give a clear and reliable picture

    of the development of the vegetation in the inland region of Godthaab Fjord.

            The diagrams may be divided into 5 well-defined zones, as will be seen

    in figure 5. The first (lowest) period is characterized by the absence of

    scrub as neither birch, nor willow, nor alder, nor juniper is present. Scat–

    tered finds of pollen grains of birch and alder are no more than can easily

    be explained, e.g., by long-distance transport from America. Pollen of willow

    is also extremely sparse, and consists principally of Salix herbacea pollen,

    which can be distinguished morphologically. On the other hand, there is a

    fairly rich flora of herbaceous plants and dwarf shrubs; of special interest

    is the presence of a series of thermophilic herbs, e.g., Atriplex , the northern

    limit of which is now in Godthaab Fjord. This shows that the climate was al–

    ready then rather favorable, the temperature being almost at the same level

    as today.

            The second period ( II ) begins with the immigration of Salix glauca .

    Shortly afterwards Alnus crispa arrives; but, contrary to the willow, alder

    does not occur with any considerable frequency for a long time. Presumably

    the summer temperature was not high enough for its full development.

            The third period ( III ) is extremely sharply marked by the immigration

    and dynamic expansion of Betula nana . It is obvious that the ecological

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    EA-PS. Iversen: Paleobotany of Greenland

    conditions must long have been favorable to B. nana ; it can have been lacking

    only for historical reasons. Therefore it attains immediately its full fre–

    quency; almost half of the total pollen is now of this species. Simultaneously

    with birch, uniper immigrates, and also [ ?] immediately attains maximal frequency.

            The fourth [ ?] period ( IV ) is the warm period in Greenland, at any rate as

    far as can be told from the vegetation aspect. The alder, which hitherto has

    been sparse, now becomes extremely frequent. Contemporary with the increase

    of the alder, Myriophyllum alterniflorum begins to bloom luxuriantly in the


            Finally, the fifth period ( V ) is marked by the dete r ioration of the climate.

    The alder scrub recedes while the Empetrum-Vaccinium heath advances (cf. also

    fig. 6).

            As mentioned earlier, the succession in the advent of the dominant plants

    is mutually consistent in all the lakes; and by means of diagrams it is pos–

    sible to correlate the vegetational development with the change of sea level.

    The bottom layer in all the lakes investigated consists of marine clay of vary–

    ing thickness. A proportion of the valley has thus been fjord, and the lakes

    have become isolated gradually as the threshold was raised above sea-level by

    the postglacial upheaval of the land.

            The diagram already shown (fig. 5) is from a lake the water level of which

    is now 100 meters above sea level. There was only a very thin layer of marine

    clay at the bottom, covered by 3 1/2 meters of lacustrine mud. We must assume

    that the lake became isolated from the fjord a short while after the ice had

    receded from the valley.

            Another diagram is from a large lake at an altitude of 50 meters above

    recent sea-level. This lake became isolated from the fjord in the middle of

    period II. The diagram, fig.6, is from a small lake at an atltitude of 8

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    EA-PS. Iversen: Paleobotany of Greenland

    meters above recent sea level; it comprises only the later periods, zone III-V.

    The diagram shows clearly that this lake became isolated shortly before the

    commencement of period IV. We may assume that during the warm period the sea

    level fell considerably below the recent shore-line.

            It is more difficult to synchronize the vegetational development in

    Greenland with that of other regions. The long-distance transport of conifer

    pollen from North America, however, affords us the means of connecting pollen

    diagrams from southwest Greenland with diagrams from the adjacent regions of

    the American Continent. As has been mentioned, this conffer pollen amounts

    to about 1% of the total, and no doubt it principally originates from the

    forests of Labrador and Newfoundland. The vegetational development of this

    region is dealt with in a paper by Wenner (). According to this author,

    after the melting of the ice sheet, a period with subarctic scrub, of birch

    and alder, intervened prior to the advent of the coniferous forest. In the

    pollen diagrams from Greenland, the conifer pollen is lacking in period I

    and most of period II, in which we have only long-distance transport of birch

    and alder; but it is constant in the following periods. The arrival of Betula

    nana roughly coincides in time with the immigration of the coniferous forest

    in Labrador. According to Wenner, this event may tentatively be dated about

    the time of transition from Boreal to Atlantic periods.

            If this holds good, zone III corresponds more or less to the Atlantic

    period in the well-known Blytt-Sernander system, and, accordingly, the warm

    period in Greenland, zone IV, synchronizes with the sub-Boreal period only.

    This feature is a remarkable deviation from the conception arrived at for

    example in Europe, where the warm period comprises not only the sub-Boreal

    but also the Boreal and Atlantic periods.

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    EA-PS. Iversen: Paleobotany of Greenland

            The usual grouping of the climatic development in postglacial time com–

    prises the following periods: the Boreal, the Atlantic, the sub-Boreal, and

    last, the sub-Atlantic periods. The three first together correspond to the

    “postglacial warm period.” Between the Boreal period and the cold late–

    glacial period we have a transition zone (the “pre-Boreal” period).

            The decline in summer temperature, which is so clearly indicated in our

    pollen diagrams by the final great fall of the alder curve, corresponds

    roughly to the well known sub-Atlantic deterioration in climate in Europe

    and elsewhere. This agrees with the fact, that the Viking colonization in

    Greenland, which is clearly indicated in the pollen diagrams, occurred a good

    while later than the decline of the alder.

            The diagram fig. 6 is from a lake in the immediate vicinity of a Norse

    farmstead. The interim of colonization is marked in the sediment by micro–

    scopic particles of charcoal, and in the pollen flora by a sharp decline in

    the curves of alder and willow, while grass and herb curves ascent. In small

    bogs situated directly on the “tun”, i.e. paddock adjacent to the homestead,

    this phenomenon is much more pronounced. This fact, together with the simul–

    taneous occurrence of a distinct charcoal layer in the bogs (cf. fig. 7),

    seem to prove that the Vikings on arrival burnt off the scrub and luxuriant

    heaths; this in turn gave rise to mats of grasses and herbs (cf. Iversen 1934).

    When the colonization ceased about a century later, the scrub regenerated. In the

    immediate vicinity of the Norse ruins, however, the fertilized soil produces a very

    luxuriant grass growth. The scrub was not able to return completely

            The end of the Norse colonization in the Godthaab Fjord region seems to

    have followed a rather dramatic course. In the bogs adjacent to the farm–

    steads (cf. fig. 7), there is an almost continuous layer of insect pupae at

    the exact horizon where various circumstances indicate that the settlements

    was abandoned. The pupae belong to a species of moth ( Agrotis oculta ), the

    008      |      Vol_V-0360                                                                                                                  
    EA-PS. Iversen: Paleobotany of Greenland

    larvae of which may occur in such enormous masses that they totally destroy the

    vegetation. In the summer of 1932 the attack in the interior of the Godthaab

    region was exceptionally serious. For moles on end, not a single green plant

    was to be seen in the Tungmeralik valley; everything was eaten off, and still

    millions of famished larvae crawled about all over the ground. A serious of

    similar disastrous attacks could have put an end to the large northern settle–

    ment (Vestri bygd) of the Norse colonization, which latter depended entirely

    on the local animal husbandry. In the southern settlement (Eystri bygd), as

    we know, the colonization continued for a longer period, and other factors must

    have occasioned the tragic extinction of the last Norse colony in Greenland.

    Among these the isolation from Europe, attacks of Eskimos, a merging of the

    Europeans with Eskimos, and a climatic development, unfavorable to a pastoral

    economy, have been suggested and discussed (cf. Nansen 1911 and 1925, Nørlund

    1924, Stefansson 1942).

            We return to the problem of the origin of the flora of Greenland. Possibly

    the most striking fact emerging from the pollen analytical investigation is the

    late arrival of dwarf birch and juniper. That the interim between the withdrawal

    of the ice from the valley and the appearance of dwarf birch covers thousands

    of years is indicated by two facts. One of these is the thickness of the sedi–

    ment deposited during that interim: in the uppermost lake it amounts to 1 meter

    of pure plankton mud, apart from the marine clay. The other fact is that in the

    same interim the coastline subsided from more than 100 meters above recent sea

    level to about 40 meters, i.e. more than 60 meters in all. Before that interim

    the inland ice withdrew from its maximal extension at the mouth of Godthaab

    Fjord almost to its recent line.

            One has to draw from this the conclusion that neither dwarf birch, nor

    juniper, nor, I think Salix glauca , survived in the nunataks of the Godthaab

    region, as in this case they would have followed the receding ice-border and

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    EA-PS. Iversen: Paleobotany of Greenland

    gradually, as the soil ripened, would have increased in frequency. It pos–

    sible that, for example, Salix glauca survived in the southern nunatak region

    region around Cape Farewell; but the fact that these plants did not, apparently,

    survive [ ?] on the numerous nunataks and other ice-free refuges in the outer region

    of the Godthaab Fjord district, shows that at any rate with these species we

    are quite near the limit of what has conceivably survived the glacial period

    in Greenland. Pollen analysis does not support the hypothesis that the southern,

    thermophilic element of the Greenland flora may have survived. Nor was this

    really to be expected, when the great decline in temperature, throughout the

    world during the glacial time, is borne in mind.

            Of special interest in the assessment of the survival problem in Green–

    land is the flora indicated in the earliest layer, which was deposited in the

    lakes shortly after the withdrawal of the ice from the valley. Table I gives

    a list of the plant species from this layer. Half of the species are very

    hardy; they ascent to great altitudes in the mountains and most of them have

    also been found in the northernmost high-arctic region of Greenland. The

    majority of these species do not seem to be better adapted to long-distance

    dispersal than are the dwarf birch and the willow. So their early occurrence

    strongly suggest that in the Godthaab region they have survived the glaciations

    on the nunataks.

            Particularly interesting is the finding of some pollen grains of Ledum ,

    which is badly adapted to long-distance dispersal., and so one must assume

    that it survived in the Godthaab region. I have found that in the inner part

    of this region, Ledum decumbens ascends a little higher in the mountains than

    Salix glauca . Thus the highest altitude at which I have found it was 1035

    meters above sea level, as compared to 1014 meters for Salix glauca and 850

    010      |      Vol_V-0362                                                                                                                  
    EA-PS. Iversen: Paleobotany of Greenland

    meters for Betula nana — both of which later, as mention e d before, failed to

    survive. If this argument holds good, we get a lowering of the vegetatio n al

    zones during the last glaciation of an order of about 1000 meters. This amount

    is somewhat lower than that arrived at in central and southern Europe. (Firbas, 1947).

            The flora of the well-known “ Jensen Nunataks ” gives one an idea of the

    plant life to be expected on the lower nunataks and semi-nunataks during

    the glacial period. The nunataks mentioned emerge at a point 60 kilometers

    from the edge of the inland ice, rising from an altitude at 1250 meters to a

    height of 1500 meters above sea level, and this great height may be regarded

    as compensating for the deterioration of temperature during the glacial period.

    From “ Jensen Nunataks ” there is a catalogue of the flora embracing 26 species,

    all distinctly arctic, Cassiope hypnoides being the only more or less wo o dy

    plant. Eight of these species are represented in the pollen flora of the

    oldest deposits (cf. Table 1).

            Apartment from the 16 hardy species mentioned in Table 1, which are sup–

    posed to be survivers, our list from the bottom layer contains a similar

    number of relatively thermophilic species, which must have immigrated to

    Greenland soon after the improvement of the climate. These species thus give

    information as to which means of dispersal were particularly effective in

    colonizing Greenland.

            The long-distance transport of seeds carried by air currents seems rather

    ineffective, as none of the early immigrants have seeds adapted to wind [ ?] dis-

    persal. On the other hand there are 4 southern pteridophytes, the micro–

    scopic spores of which, of course, may easily be carried to Greenland by air


            Transport by currents of the ocean , possibly on drifting ice, is certainly

    011      |      Vol_V-0363                                                                                                                  
    EA-PS. Iversen: Paleobotany of Greenland

    rather effective. Yet, the course of the arctic currents suggests that only

    Icelandic and not American plants may be carried to Greenland by this means.

    Two species from the earliest deposits have presumably arrived in this way.

            A little higher in zone I, Archangelica officinalis ( Angelica archangelica )

    immigrates. This species is not found in America, but the fruits may have

    been carried from Iceland on ice-floes which drifted out into the polar cur–

    rent and subsequently lodged on the south or west coast of Greenland. The

    great buoyancy of the fruits would then facilitate their being carried up onto

    the beach when the ice melted.

            The majority of the immigrants — all water marsh plants — have, how–

    ever, arrived epizoically, being transported by birds. Of special interest

    is the immigration of Lomatogonium rotatum . This annual prefers wet, [ ?]

    clayey soil and it produces a profusion of small seeds, which easily adhere,

    together with particles of clay, to the feet of geese and wading birds. Kerner, (1898, p.621) has shown the effectiveness of this

    kind of dispersal of small annuals on wet clayey soil.

    Canada Lomatogonium it has been carried to southern Greenland, and thence on the Iceland

    where the migration has so far come to an end.

            So the significance of epizoic long-distance transport of birds is obvious.

    Lately this has been doubted with reference to the fact that birds generally

    clean themselves carefully before they set off on a long flight. It is, how–

    ever, also known that birds which are not quite “fit,” neglect their toilette.

    At any rate birds cannot get rid of what sticks to their feet immediately

    before or at the moment they take to their wings. The rapid immigration of

    species of Potamogeton to Greenland strongly suggests that other than small

    seeds may be transported in this manner.

            Thus a knowledge of the migration routes of the birds is of importance

    when dealing with our problem. It is fortunate that the routes of the most

    012      |      Vol_V-0364                                                                                                                  
    EA-PS. Iversen: Paleobotany of Greenland

    important migratory birds of Greenland have been determined in the last few

    years by Dr. Finn Salomonsen (). The map (fig. 8) is based on information

    in Salomonsen’s work, and shows the most important migratory routes of the

    geese. The bulk of the geese winter in the British Isles. Iceland is a

    resting-place on the trip. Every spring, tens of thousands of geese leave

    Iceland. Some fly to the Cape Farewell region, and thence to the North fol–

    lowing the West coast. A large proportion rest at Angmagssalik on the east

    coast of Greenland and subsequently cross the inland ice. Other species

    fly to the Scoresby Sound region. Finally, the American stock of the Brent

    Goose makes a non-stop flight from Ungava Bay in Labrador to Western Green–

    land. This route is of special interest, as it starts so far south. It is

    inconceivable that these immense numbers of geese would not occasionally

    carry seeds with them to Greenland. I suppose that Betula nana has arrived

    in Greenland from Iceland (or Scotland) by this means, particularly as one

    of the geese, the White-fronted Goose, li,es to feed on scrub and heath.

    Other birds from Greenland follow similar routes, but it might be worth

    noting, that, so far as is known, there are no migratory routes between the

    Scandinavian peninsula and Greenland.

            The step-by-step immigration of southern plants following the route

    North of Baffin Bay was only possible in Greenland during the warm period,

    the period IV and one can scarcely at present point out any species whose

    distribution makes this route of immigration seem probable.

            A final group of immigrants was brought to Greenland by man. Ostenfeld

    (1926) estimated that about 50 plant species were brought to Greenland from

    Iceland by the Norsemen. The number, as emphasized by Porsild (1932) is

    probably too high. We can, of course, be quite certain only in the case of

    013      |      Vol_V-0365                                                                                                                  
    EA-PS. Iversen: Paleobotany of Greenland

    e.g. Capsella , Stellaria media , and Polygonum aviculare sl. that have been

    found in deposits from Norse culture; but it is evident that plants occurring

    in natural habitats may also have been brought over in a similar manner. We

    must also assume that the Norsemen brought some plant species from America,

    where they went among other reasons to get timber.

            Perhaps Sisyrinchium montanum was brought to Greenland in this way.

    Indeed it may be the only thermophilic plant in Greenland of western origin,

    the immigration of which is not easily explained by natural means of dis–

    persal, e.g. during the warm period.

            It must be remembered that plants which now have a peculiar, widely

    scattered distribution, may in early times have had a much wider distribution;

    thus the immigration difficulty may be regarded as negligible, so long as

    means of crossing Davis Strait were present. Cases of postglacial restrict–

    tions to scattered areas have been disclosed in recent pollen analytical in–

    vestigation [ ?] in Northern Europe.

            Greenland is a vast region, and an isolated investigation of the Pleisto–

    cene and recent paleobotany as of course a limited application outside the

    area of investigation. Northern and East Greenland, up to the present, remain

    totally unexplored in this conection.

    014      |      Vol_V-0366                                                                                                                  

    Fig. 5.

    Fig. 6

    Fig. 7.

    015      |      Vol_V-0367                                                                                                                  

    8 Migration routes of geese (according to Finn Salomonsen 1950).

    O raesting places —1 goose species. ≣ 4 goose species

    016      |      Vol_V-0368                                                                                                                  
    EA-PS. Iversen: Paleobotany of Greenland


    1. Bőcher f , T.W. “Biological distributional types in the flora of Greenland.”

    Medd.Grøn. vol.106, no.2, pp.312-20, 1938.

    2. ----. “Contributions to the flora and plant geography of West Greenland.I,

    Selaginella rupestris and Sisrinchium montanum .” Medd.Grøn .

    vol.147, no.3, 1948.

    3. Dahl, Eilif. “Studies in the macrolichen flora of South West Greenland.”

    Medd.Grøn. vol.150, no.2, p.164, 1949.

    4. Firbas, Fr. “Über die späteiszeitlichen Verschiebungen der Waldgrenze.”

    Die Naturwissenschaften , no.4, p.1, 1947.

    5. Gelting, P. “Studies on the vascular plants of East Greenland between

    Franz Joseph Fjord and Dove Bay.” Medd.Grøn . vol.101, No.2, 1934.

    6. ----. “Üher pleistozäne Pflanzenrefugien in Grønland.” Mitt.Naturf.Gesellsch .

    vol.17, no.4, pp.74-96, 1941.

    7. Iversen, Johns. “Mooregeologische untersuchungen auf Grőnland.” Medd.Dansk

    Geol.Foren København, vol.8, 1934.

    8. ----. “Et botanisk Vidne om Nordboernes Vinlandsrejser.” Naturhist.Tidende

    Københaven, vol.2, pp.113-16, 1938.

    9. Kerner, A. Pflanzenleben, vol.2, p.621, 1898.

    10. [ ?] Nansen, F. In Northern Mists, London and New York, 1911.

    11. ----. “Klimat-Vekslinger i Nordens Historie.” Norske Videnskaps-Akad. I.

    Matem. -Naturvid. Kl.25, no.3, Oslo, 1925.

    12. Nørlund, P. “Did a deterioration of the climate occur in Greenland in the

    late Middle Ages?” Medd.Grøn . vol.67, 1924.

    13. Ostenfeld, C.H. “The flora of Greenland and its origin.” Kgl. Danske Vidensk.

    Selsk.Biol.Medd. København, vol.6, no.3, 1926.

    14. Polunin, N. “The birch ‘forests’ of Greenland.” Nature, vol.140, pp.939-40,


    15. ----. “Notes on a botanical journey to S.W. Greenland, 1937.” Kew Bull.of

    Misc.Inf ., no.3, pp.89-98, 1938.

    16. Porsild, M.P. “Alien plants and apophytes of Greenland.” Medd.Grøn . vol.92,

    no.1, 1932.

    17. Salomonsen, Finn. The Birds of Greenland . Ejnar Munksgaard, Copenhagen, 1950.

    017      |      Vol_V-0369                                                                                                                  
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    18. Stefansson, V. Greenland. New York, Doubleday, Doran & Co., pp.160-97,


    19. Warming, E. “Om Grőnlands vegetation.” Medd.Grőn. vol.12, 1888.

    20. Wenner, C.G. “Pollen diagram from Labrador,” Geografiska Annaler ,

    Stockholm, vol.29, p.137, 1947.


    Johns. Iversen

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