If you do not need this report after it has served your purpose, please return it to 

the Geological Survey, using the official mailing label at the end

UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Professional Paper 186-F

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA

BY

CHARLES B. READ AND ROLAND W. BROWN

Shorter contributions to general geology, 1936

(Pages 105-131)

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1937

For sale by the Superintendent of Documents, Washington, D. C. ------ Price 15 cents
CONTENTS

Page

Abstract._-_____-__-____-_-_--_-_-_-_-_________-__ 105

Introduction __ _____________________________________ 105

Historical account.__________________________________ 106

Bibliography._.__-__-_-.-____-_---________-_--______ 107

Systematic descriptions.____________________________ 108

Tempskyaceae.________________________________ 108

Genus Tempskya Corda (emend.)____________ 108

Tempskya knowltoni Seward------_-__-----_-_ 112

Tempskya grandis Read and Brown, n. sp_____ 114

Tempskya minor Read and Brown, n. sp_______ 117

Tempskya whitei Berry______________________ 119

Systematic descriptions—Continued.

Tempskyaceae—Continued. Page

Tempskya sp___-________-_-____-__-__--_--_ 119

Synopsis. _________--__-_-__-___-__----_---_--_ 119

Taxonomic position______________-_______-_--__---_- 120

Affinities of Tempskya....----------------------- 120

Interrelationships of the species__________________ 122

Probable habit of Tempskya- ________________________ 122

Stratigraphic significance of the Tempskyaceae- ._______ 124

Conclusions _._____________-_______-_--_----__---___ 129

ILLUSTRATIONS

Page

PLATE 27. Chart showing occurrence of Tempskya,---., 124 

28-43. Species of the genus Tempskya.-- _______ 131

FIGURE 2. Sketch of a transverse section of Tempskya 

knowltoni Seward showing the dorsiventral 

orientation of the stems in the root mass__ 108 

3. Sketch of a transversely cut face of Tempskya 

grandis Read and Brown, n. sp., showing 

the radial orientation of the dorsiventral 

stems in the false trunk_________________ 108

FIGURE 4. Sketch of Tempskya minor Read and Brown, 

n. sp., showing the prominently dorsiventral orientation of the stems in the false 

trunk_ ________________________________

5. Sketches showing in diagrammatic fashion the 

development of the leaf trace in Tempskya..

6. Map showing Tempskya localities in the United 

States________--________-____-____.-_

Page

108

109

125
AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA

By CHARLES B. READ and ROLAND W. BROWN

ABSTRACT

The Tempskyas are a group of ferns, known at present from 

remains of stems, leaf bases, and roots found in rocks of Cretaceous age in Europe and North America. They were first 

recorded in 1824 by Stokes and Webb under the name Endogenites. In 1845 Corda, after examination of similar material 

from Bohemia, established Tempskya as a genus, and some 

years later the identity of Stokes and Webb's specimens became 

known. During the later part of the nineteenth century several 

investigators, among them Feistmantel, Velenovsky, and 

Seward, had occasion to deal with the genus. Owing to the 

very poor preservation of most of the specimens the investigators 

were not able to recognize the true nature of the materials, 

although they were admitted to be fern stems. The prevalent 

opinion was that the structure was similar to that of Protopteris.

In 1911 Kidston and Gwynne-Vaughan published a study of 

a well-preserved Tempskya from the Ural Mountains and definitely established the fact that in Tempskya the large trunklike 

mass that is commonly preserved consists of an aggregate of 

stems bound together by a thick mat of roots into a false trunk.

In America the first record of Tempskya was made in 1911, 

when Berry described Tempskya whitei from the Patapsco 

formation (Lower Cretaceous) of Maryland. In 1924 Seward 

published an account of a very well preserved specimen from 

what is now known to be the Colorado shale (Upper Cretaceous) 

near Harlowton, Mont. In that contribution considerable 

space was devoted to an analysis of habit and affinities, and the 

conclusion was reached that the false trunk was subterranean, 

obliquely ascending, and that the plant was of schizaeaceous 

affinities.

The present paper sets forth the generic characters and, after 

presenting a summary of Tempskya knowltoni Seward, describes 

Tempskya grandis, Tempskya minor, and Tempskya sp. from 

strata of Upper Cretaceous age in western Wyoming and adjacent 

portions of Idaho and Utah. A few observations are made 

on Tempskya whitei Berry. All these species conform to the 

generic diagnosis based on Tempskya rossica as regards the 

dorsiventral stems, the siphonosteles, the two-ranked leaves, and 

the diarch roots. All have developed the false-trunk habit. 

It is shown that this false trunk may be dorsiventral or radial 

in its symmetry and that this symmetry appears to be constant 

within a species. It is suggested that the radially arranged 

false trunks must have stood upright and that the dorsiventral 

false 'trunk may have been characteristic of lianalike or cliffclimbing ferns, or even of partial epiphytes. False trunks of a 

similar type are not known among either modern ferns or other 

groups of fossil ferns.

The problem of the exact affinities of Tempskya is not solved. 

Tempskya is unquestionably one of the Leptosporangiatae and 

may be related to any one of several families. A temporary 

family, the Tempskyaceae, is erected for the genus.

The stratigraphic range of the genus appears to be from lowermost Lower Cretaceous to Senonian. In western America it is 

apparently restricted to the Colorado group.

INTRODUCTION

In the annals of paleobotany the genus Tempskya 

has long occupied a very speculative position. It 

was reported under the name Endogenites as early 

as 1824 and elevated to its present status as the genus 

Tempskya in 1845, but its true nature was not realized 

until 1911. Since then there has been some progress 

by way of occasional contributions tending to show 

the diversification of the genus.. However, several 

important issues remain to be decided. There are 

conflicting points of view concerning the habit and 

taxonomic position of Tempskya among the ferns.

It is the purpose of the writers of this paper to review 

the genus and the various opinions that have been 

expressed concerning it. New material from the 

western United States is described, some of which has 

a significant bearing on the habits of the genus. Tempskya knowltoni Seward has been redescribed, not 

because of any fault in Seward's account but because 

of the desirability of emphasizing the distinctive 

characters of this fossil by way of contrast in making 

the specific differentiation of the other materials. 

Little attempt has been made in the past to discuss 

the stratigraphic range of Tempskya. The writers 

have essayed to compile the facts concerning its occurrence hi an effort to estimate the value of the several 

species as age indexes.

The assistance and encouragement of the officials of 

the United States Geological Survey in the preparation of this report is acknowledged with pleasure. 

J. B. Reeside, Jr., has been especially interested in the 

work and has given many valuable suggestions. The 

late Dr. David White likewise cheerfully contributed 

advice and constructive criticism. G. R. Mansfield, 

W. W. Rubey, and J. S. Williams, of the Geological 

Survey, Prof. G. R. Wieland, of Yale University, and 

Prof. S. H. Knight, of the University of Wyoming, 

have collected most of the new material during the 

course of various geologic investigations in southeastern Idaho and adjacent parts of Wyoming. Dr. 

R. S. Bassler has generously permitted the preparation 

of several unusually large thin sections in the laboratories of the United States National Museum, and 

K. J. Murata has prepared most of the excellent 

sections of the new material here illustrated.

105
106 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

HISTORICAL ACCOUNT

The earliest record of Tempskya that the writers 

have been able to find is an account of Endogenites 

erosa given by Stokes and Webb : in 1824 in their 

report on plant material collected in Tilgate Forest by 

Mantell. As the generic name indicates, the silicified 

remains were regarded as monocotyledonous forms, 

possibly palms. In 1832 Cotta 2 referred similar 

material to Porosus marginatus and differed with Stokes 

and Webb in pronouncing the material to be portions 

of a large fern stem. In the following year this same 

opinion was expressed by Mantell 3 after a careful 

examination of the specimens that he had collected 

about 10 years before. In 1836 Fitton gave an account 

of similar materials found near Hastings and referred 

them to Endogenites erosa.

In 1845 a noteworthy contribution was made by 

Unger,4 who inclined to the opinion that Endogenites 

erosa was simply a mode of preservation of Protopteris 

and introduced evidence in support of this idea.

In the same year Corda 5 published the results of his 

observations on large collections of petrifications and 

erected in honor of Tempsky a new genus, Tempskya, 

for four specimens of silicified material from as many 

localities, presumably in Bohemia and adjacent regions. 

The generic diagnosis is as follows:

Truncus * * * Rhachis rotundata, plicata vel alata; 

cortice crassiuscula, fasciculis vasorum ternatis, majori clause 

vel lunulato et supra incurvo, minoribus oppositis lunulatis. 

Radices minutae numerosissimae; fascicule vasorum centrali 

unico.

Tempskya was placed in the Phthoropterides, and the 

interpretation of the silicified masses was that they 

were branched petioles sheathed in a thick mat of 

roots. Four species—Tempskya pulchra, T. macrocaula, T. microrrhiza, and T. schimperi—were described 

on rather questionable grounds. As the preservation is 

very poor, this historically important material does not 

furnish many data of value in the study of other specimens. Corda was apparently unaware of the occurrence 

of similar fossils in England, for no mention is made of 

Endogenites erosa.

The first intimation that Tempskya is other than the 

outer or perhaps distal portion of a tree-fern axis is 

found in a paper by Schenk.6 In his opinion Tempskya 

was a complete stem of possibly marattiaceous affinities, with numerous vascular bundles sheathed in a 

parenchyinatous and sclerenchymatous ground mass.

i Stokes, Charles, and Webb, P. B., Description of some fossil vegetables of the 

Tilgate Forest in Sussex: Geol. Soc. London Trans., ser. 2, vol. 1, pp. 421-424, pis. 

45-47, 1824.

* Cotta, C. B., Die Dendrolithen, p. 41, pi. 8, figs. 4, 5, 1832.

* Mantell, G. A., The geology of the Southeast of England, p. 236, pi. 1, figs 4,5,7, 

1833.

4 Unger, Franz, Synopsis plantarum fossilium, p. 107, 1845.

5 Corda, A. J., Flora protogaea; Beitrage zur Flora der Vorwelt, p. 81, 1845.

e Schenk, August, BeitrSge zur Flora der Vorwelt; IV, Die fossile Flora der nordwestdeutschen Wealdenformation: Palaeontographica, vol. 9, pp. 203-266, pis. 42-43, 

1871.

In 1872 Feistmantel 7 suggested that Tempskya was 

not a genus but rather a mode of preservation of several 

distinct types of fern stems. Protopteris sternbergii 

Corda was suggested as one species that might be correlated with tempskyoid preservation. This opinion is 

very interesting and seems to have made a profound 

impression on contemporary investigators, for several 

papers were soon published in support of this theory. 

Velenovsky 8 accepted this view and produced new 

evidence which seemed to corroborate this interpretation.

A very valuable account of the literature on Tempskya is given by Seward in his catalog of Wealden 

plants.9 Feistmantel's ideas were questioned but not 

definitely discarded. Seward's general conclusions 

are as follows:

In Tempskya schimperi we have masses of branched diarch 

fern roots associated with petiole axes, which occasionally afford 

evidence of branching; probably some forms of Tempskya and 

Protopteris are very closely related, if not identical plants; but, 

so far as English specimens are concerned, there is an absence of 

any direct proof of such organic connection between the two 

fossils, as Feistmantel and Velenovsky have previously suggested.

In 1897 Stenzel 10 discussed the question at length 

and decided that the morphologic make-up of the 

fossils did not entirely justify any conclusion so far 

reached as to their exact nature. He offered several 

possible explanations:

1. Lateral organs of a tree fern growing downward and 

encased in downward-growing roots. (This hypothesis is similar 

to that suggested by Corda, although not identical with it.)

2. Independent stems climbing upward between roots.

3. Upward-growing and branching fern stems encased in their 

own downward-growing roots.

Of these explanations Stenzel inclined toward the 

last, although he preferred to leave the question open 

and did not finally commit himself.

It remained for Kidston and Gwynne-Vaughan to 

determine definitely the exact nature of Tempskya, 

which they did in an excellent account u of Tempskya 

rossica, a new species described from the basin of the 

Karaganda River in Russia. Unfortunately the geologic age of the material is uncertain, because it seems 

to have been reworked from older strata into a conglomerate of Tertiary age. It must be borne in mind 

that before the discovery of T. rossica all the specimens known were poorly preserved and did not permit 

detailed examination of the tissues. In the type of 

T. rossica the preservation is excellent, and as a result

7 Feistmantel, Ottokar, tiber Baumfarrenreste der bohmischen Steinkohlen-, 

Perm- und Kreideformation: K. bohm. Gesell. Wiss. Abh., Folge 6, Band 6, p. 22, 

1872.

8 Velenovsky, Josef, Die Farne der bohmischen Kreideformation: K. bohm. 

Gesell. Wiss. Abh., Folge 7, Band 2, Nr. 8, p. 25, 1888.

9 Seward, A. C., The Wealden flora, part 1; Catalogue of the Mesozoic plants in 

the Department of Geology, British Museum (Natural History), pp. 148-159,1894.

1° Stenzel, K. G., Verkieselte Farne von Kamenz in Sachsen: K. min. Mus. Dresden Mitt., Heft 13, p. 3, 1897.

11 Kidston, Robert, and Gwynne-Vaughan, D. T., On a new species of Tempskya 

from Russia: Russ. k. min. Gesell. Verb., Band 48, pp. 1-20, pis. 1-3, 1911.
AMEEICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA 107

the investigators were able to clear up many unsettled 

points. They finally concluded that the siliceous 

masses were false stems—that is, composed of a single 

dichotomously branching stem system encased in a 

thick mat of adventitious roots. The stems were 

highly sclerenchymatous, solenostelic, and dorsiventral. The roots were diarch. As regards the habit, 

the false stems were suspected of having stood erect 

to a height of several feet and of having produced a 

crown of leaves. The affinities of Tempskya were left 

unsettled, although it was held that they were with the 

Leptosporangiatae.

In the same year Berry 12 described an American 

species, Tempskya whitei, from the Patapsco (Lower 

Cretaceous) deposits of the Atlantic Coastal Plain. 

The preservation is poor, however, and no additions 

to the anatomical knowledge of the genus were made.

Stopes,13 in her discussion of the Lower Greensand 

plants of Great Britain, presented a summary of the 

progress in the* study of Tempskya and redescribed 

Tempskya erosa Stokes, Webb, and Mantell. A reconstruction of the probable aspect of Tempskya rossica 

Kidston and Gwynne-Vaughan was included and shows 

a massive erect false stem bearing a terminal cluster of 

leaves.

In 1924 u Seward described a very well preserved 

Tempskya from Montana. This fossil had been collected by A. C. Silberling in 1908 in the Musselshell 

Valley and had been in the collections of the United 

States Geological Survey for a number of years. Dr. 

Knowlton's activities had been so intensively directed 

in other fields that he had never been able to investigate it and finally transmitted the complete specimen 

to Seward. The species was named Tempskya knowltoni and is of Colorado age. It presents several interesting features, among which is an apparent dorsiventrality of the entire false stem. This caused Seward 

to conclude that T. knowltoni was "a root-encircled 

bundle of stems, obconical and tapering, lying obliquely 

in the soil, a few of the stem branches bearing crowded 

fronds near the ground level." The affinities of 

Tempskya were held to be with the Schizaeaceae, in 

view of the stelar similarities, the similarity of certain 

spores found by Boodle in an English specimen to 

those of schizaeaceous ferns, and finally the alleged 

similarity of certain sporangia found in the root mat 

of T. knowltoni to the type of sporangia characteristic 

of the Schizaeaceae.

BIBLIOGRAPHY

The following list gives the publications that contain descriptions and discussions of the genus Tempskya 

and its several species.

12 Berry, E. W., Maryland Geol. Survey, Lower Cretaceous, p. 298, pis. 37, 38,1911.

13 Stopes, M. C., The Cretaceous flora, part 2, Lower Greensand (Aptian) plants 

of Britain: Catalogue of Mesozoic plants in the British Museum (Natural History), 

pp. 9-21, text figs. 2-5, 1915.

H Seward, A. C., On a new species of Tempskya from Montana, Tempskya knowltoni, sp. nov.: Annals of Botany, vol. 38, no. 151, pp. 485-507, text figs. 1-3, pis. 16,17,1924.

Berry, E. W., Maryland Geol. Survey, Lower Cretaceous, pp. 

295-299, pis. 37, 38, 1911.

Boodle, L. A., Spores in a specimen of Tempskya (Endogenites): 

Annals of Botany, vol. 9, pp. 137-141, text figs. 1-4, 1895.

Bower, F. A., The ferns, vol. 2, pp. 106, 169, 1926.

Brongniart, Adolphe, Tableau des genres de v6g6taux fossiles, 

p. 107, 1849.

Bronn, H. G., Index paleontologicus nomenclator, vol. 1, p. 461, 

1848.

Bronn, H. G., and Roemer, Ferdinand, Lethaea geognostica, 

vol. 2, p. 46, pi. 28, fig. 8a, b, c, 1851.

Carpentier, Alfred, La flore wealdienne de Feron-Glageon 

(Nord): Soc. geol. Nord Mem., vol. 10, 1927.

Corda, A. J., Flora protogaea; Beitrage zur Flora der Vorwelt, 

pp. 81-83, 1845.

Cotta, C. B., Die Dendrolithen, pp. 37-44, pi. 8, figs. 4, 5, 1832.

Dixon, Frederick, Geology of Sussex, 2d ed., p. 282, 1878.

Dunker, Wilhelm, Monographic der norddeutschen Wealdenbildung, p. 17, pi. 3, figs. 1, la, Ib, 1846.

Engler, Adolf, and Prantl, K. A. E., Die natiirlichen Pflanzenfamilien, Teil 1, Abt. 4, p. 512, 1902.

Ettingshausen, Constantin von, Beitrag zur naheren Kenntniss der Flora der Wealden Periode: K.-k. geol. Reichsanstalt Abh., vol. 1, pt. 2, no. 2, p. 19, 1852.

Feistmantel, Ottokar, Uber Baumfarrenreste der bohmischen 

Steinkohlen-, Perm- und Kreideformation: K. bohm. 

Gesell. Wiss. Abh., Folge 6, Band 6, p. 22, 1872.

Fitton, W. H., Observations on some of the strata between the 

Chalk and Oxford oolite in the Southeast of England: 

Geol. Soc. London Trans., ser. 2, vol. 4, p. 172, pis. 19, 20, 

text fig. 1, 1836.

Giebel, C. G., Deutschlands Petrefacten: Fossile Pflanzen, 

vol. 1, p. 66, 1852.

Gutbier, August von, Die Versteinerungen des Rothliegenden 

in Sachsen, p. 17, 1849.

Gwynne-Vaughan, D. T. See Kidston, Robert.

Hirmer, Max, Handbuch der Palaobotanik, p. 681, 1927.

Hosius, August, and Marck, W. von der, Die Flora der westfalischen Kreideformation: Palaeontographica, vol. 26, p. 

192 (68), pi. 39, figs. 161-163, 1880.

Kidston, Robert, and Gwynne-Vaughan, D. T., On the fossil 

genus Tempskya: British Assoc. Adv. Sci. Rept., Sheffield, 

p. 783, 1910.

Kidston, Robert, and Gwynne-Vaughan, D. T., On a new species 

of Tempskya from Russia: Russ. k. min. Gesell. Verh., 

Band 48, pp. 1-20, pis. 1-3, 1911.

Knowlton, F. H., Plants of the past, pp. 143-146, text fig. 67,1927.

Mantell, G. A., Illustrations of the geology of Sussex; Fossils 

of the South Downs, p. 42, 1822.

Mantell, G. A., in Stokes, Charles, and Webb, P. B., Description of some fossil vegetables of the Tilgate Forest in Sussex: Geol. Soc. London Trans., ser.-2, vol. 1, p. 423, pi. 

46, figs. 1, 2; pi. 47, figs. 5 a, b, 1824. (No author's name 

given.)

Mantell, G. A., Illustrations of the geology of Sussex; Fossils 

of the Tilgate Forest, p. 54, pi. 3, figs. 1, 2; pi. 3 [so numbered in the book], fig. 5, 1827.

Mantell, G. A., The geology of the Southeast of England, p. 

236, pi. 1, figs. 4, 5, 7, 1833.

Martin, P. I., A geological memoir on a part of western Sussex, 

p. 41, 1828.

Morris, John, A catalog of British fossils, 2d ed., p. 8, 1854.

Reuss, A. E., Die Versteinerungen der bohmischen Kreideformation, p. 87, pi. 47, fig. 7, 1845-46.

Schenk, August, Beitrage zur Flora der Vorwelt; IV, Die fossile Flora der nordwestdeutschen Wealdenformation: 

Palaeontographica, vol. 19, p. 259, pi. 42, fig. 4; pi. 43, 1871.

Schimper, W. P., Trait6 de pa!6ontologie v6g6tale, vol. 1, p. 

698, 1869.
108 SHORTEE CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

Seward, A. C., The Wealden flora, Part I: Catalogue of the 

Mesozoic plants in the Department of Geology, British 

Museum (Natural History), pp. 148-159, 1894.

Seward, A. C., On a new species of Tempskya from Montana, 

Tempskya knowltoni, sp. nov.: Annals of Botany, vol. 38, 

no. 151, pp. 485-507, text figs. 1-3, pis. 16, 17, 1924.

Stokes, Charles, and Webb, P. B., 1824. See Mantell, G. A., 

1824.

Stopes, M. C., The Cretaceous flora; Part II, Lower Greensand 

(Aptian) plants of Britain: Catalogue of the Mesozoic 

plants in the British Museum (Natural History), pp. 9-21, 

text figs. 2-5, 1915.

linger, Franz, Synopsis plantarum fossilium, p. 107, 1845.

Unger, Franz, Genera et species plantarum fossilium, p. 201, 

1850.

Velenovsky, Josef, Die Fame der bohmischen Kreideformation: 

K. bohm. Gesell. Wiss. Abh., Folge 7, Band 2, p. 23, 1888.

SYSTEMATIC DESCRIPTIONS

TEMPSKYACEAE « 

Genus TEMPSKYA Corda (emend.)

1845. Corda, A. J., Flora protogaea; Beitrage zur Flora der

Vorwelt, p. 81. 

1911. Kidston, Robert, and Gwynne-Vaughan, D. T., On a new

species of Tempskya from Russia: Russ. k. min. Gesell.

Verh., Band 48, pp. 1-20, pis. 1-3.

The generic diagnosis given by Kidston and GwynneVaughan is as follows:

Stems of small diameter, erect, dichotomous, and embedded 

in a felted mass of their own adventitious roots. Dorsiventral, 

with the leaves in two rows on one side of the stem and roots 

alone on the opposite side. Vascular system of stem a solenostele. 

Leaf trace departs as a single strand. Roots diarch. 16

In Corda's account 17 of Tempskya four species— 

Tempskya pulchra, T. macrocaula, T. microrrhiza, and 

T. schimperi—are described in the order named. According to strict botanic nomenclature one of these, 

preferably the first, should be designated as the genotype. The writers, although they heartily approve of 

the several codes of rules followed by systematists, 

think it is desirable here to depart from their general 

practice and recommend that Tempskya rossica Kidston 

and Gwynne-Vaughan be admitted as the type of the 

genus. The reasons are several. In the first place, 

T. pulchra, the first species named by Corda, is very 

imperfectly known and has not been carefully investigated, to the writers' knowledge, since Corda's publication. The same is true of his other three species. 

Furthermore, the preservation of the material, if several later accounts are correct, is very mediocre, so that 

many of the details are lost and specific differentiation 

is questionable. On the other hand, T. rossica is a 

beautifully preserved fossil and has been carefully 

studied by two very distinguished investigators of plant 

morphology. In consequence a wealth of detail has 

been recorded. Therefore, T. pulchra Corda at best

uSee p. 122.

is Kidston, Robert, and Gwynne-Vaughan, D. T., op. cit., p. 13, 1811.

»' Corda, A. J., op. cit., pp. 81-82, 1845.

can be recognized as no more than a nominal genotpye, 

and T. rossica must be taken as the "working" type.

Gross aspect oj Tempskya.—As viewed with the naked 

eye or under a low-power hand lens, specimens of

FIGURE 2.—Sketch of a transverse section of Tempskya, knowltoni Seward showing the 

dorsiventral orientation of the stems in the root mass.

Tempskya bear a striking similarity to fragments of 

palm stem. Plate 28, figures 1 and 2', and plate 29,

FIQUKE 3.—Sketch of a transversely cut face of Tempskya grandis Read and Brown, 

n. sp., showing the radial orientation of the dorsiventral stems in the false trunk. 

TJ. S. Nat. Mus. 39267. Half natural size.

figures 1 and 2, convey some idea of the general aspect 

of transverse faces of the "false stem" with a magniFIQUEE 4.—Sketch of Tempskya minor Read and Brown, n. sp., showing the predominantly dorsiventral orientation of the stems in the false trunk. TJ. S. Nat. Mus. 

39259. Half natural size.

fication of a few diameters. There is a groundmass 

of small organs, round or elliptic in cross section that 

suggest the scattered collateral vascular bundles of a 

palm trunk, and embedded in this mass are a few
AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA 109

larger and more irregularly shaped organs that suggest 

the adventitious roots so commonly found in the outer 

region of the basal portion of the stem of an arborescent 

monocotyledon. The former are adventitious diarch 

roots; the latter are stems embedded in this felted root 

mass, and the whole forms what is termed a false stem.

which is sketched from a section of Tempskya knowltoni 

Seward, indicates that there is apparently a strong 

dorsiventrality in the false stem—that is, the stems are 

so oriented that their leaf traces pass off in approximately the same direction throughout the false stem. 

Another diagram of the arrangement of stems within

'.ph

a

FIGUEE 5.—Sketches showing in diagrammatic fashion the development of the leaf 

trace in Tempskya. a, A stem just prior to the gapping by an emerging leaf trace, 

which is shown in the upper right portion of the stele (p, pith; I. ph, internal 

phloem, pericycle, and endodermis; x, xylem; o. ph, external phloem, pericycle, 

and endodermis; c, cortex). 6, Leaf trace forming a distinct bulge outward from 

the main axis. To the left is another trace in the cortex, c, Gap of right trace just

The stems, as has been previously demonstrated 18 

and as is again shown in this paper, are dorsiventral 

and appear to be a much-branched axial system of a 

single plant rather than a number of individuals of 

gregarious disposition. It follows, therefore, that a 

survey of the orientation of the individual stems may 

furnish information of great value for the determination 

of the habit of the plant. Text figures 2 to 4 have been 

prepared to demonstrate this plainly. Text figure 2,

>• Kidston, Robert, and Qwynne-Vaughan, D. T., op. cit., 1911.

forming and terminal portions of left trace showing a tendency to recurve. d, Bight 

trace has just passed into the inner cortex, the gap having closed behind it, and left 

trace has become still more recurved, e, Left trace has passed into the base of the 

phyllopodium, whereas the right trace is gradually emerging in the cortex. Enlarged about 10 diameters.

the groundmass of roots is seen in text figure 4, which is 

drawn from the specimen that is described on page 117 

as T. minor, a new species. A similar dorsiventral 

arrangement is at once manifest. Figure 3 shows the 

condition in T. grandis, another new species. A striking lack of similarity to T. knowltoni, so far as the 

orientation of the stems is concerned, is at once apparent. The symmetry of the dorsiventral stems is 

radial within the false stem—that is to say, the leaf 

traces are regularly directed toward the nearest point
110 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

on the periphery. T. rossica Kidston and GwynneVaughan shows symmetry perhaps intermediate between radial and dorsiventral.

In conclusion, two conditions prevail in the genus 

Tempskya, so far as the orientation of the dorsiventral 

stems within the false stem is concerned—an apparently 

well-established dorsiventral arrangement in some 

species and an apparent radial arrangement in other 

species. Transitional forms may occur as well. The 

bearing of these facts on the probable habit of Tempskya 

is discussed elsewhere (pp. 122-124).

Branching of the stem.—The numerous thin sections 

that have been prepared from the several species of 

Tempskya show that frequent dichotomy of the stem 

is characteristic of the genus as a whole. That the 

forks of this dichotomy are equal in size is obvious 

from plate 29, figure 3. No suggestion of lateral 

branching has been observed. The writers attempted 

to determine the distance between these successive 

bifurcations by cutting a block several inches long 

into serial sections, but they found that this character 

is so variable that it has little value either for morphologic or for taxonomic considerations.

Disposition of the tissues in the stem.— The stem of 

Tempskya is characterized by a siphonostele, as is 

clearly shown in plate 30, figure 1, and plate 31, 

figures 1 and 2. The periphery of the stem is a layer 

a few cells thick of only slightly modified parenchyma 

and constitutes what may be termed the outer cortex. 

The epidermis, in the individuals that the writers 

have observed, is in a very poor state of preservation 

and rarely furnishes information relative to emergences 

which might be of systematic value. Beneath this 

thin outer cortex is a rather thick zone of highly 

sclerenchymatous tissue, which in many specimens 

makes up the bulk of the cortex. This tissue is here 

referred to as the middle or sclerenchymatous cortex. 

The cells that make up this tissue are isodiametric in 

cross section, their lumens are minute and commonly 

appear to have been congested with some gummy 

material, and when viewed in longitudinal section 

they are elongate. They are typical fibrous elements 

similar to those which may be observed in the mechanical tissue of the bracken fern or in the so-called "bast" 

of the higher plants.

Within the zone of sclerenchyma there is a variable 

but generally thin zone of inner parenchymatous cortex. 

In Tempskya rossica, T. knowltoni, and T. minor this 

layer is so homogeneous that it does not merit a detailed description. In T. grandis, however, the inner 

cortex is more complex. There the zone is rather 

broad, sometimes rivaling the sclerenchymatous sheath 

in breadth. The bulk of the tissue is large-celled 

parenchyma, but near the inner margin there is an 

irregular layer of sclerotic tissue (pi. 34, fig. 4). Isolated strands of this tissue also occur. Within is a 

narrow zone of parenchyma bordering the endodermis.

The width of this inner cortex is a character of considerable value in taxonomic work on the genus, and 

obviously the varying complexity, as typified on the 

one hand by Tempskya knowltoni and on the other by 

T. grandis, is of specific worth.

The cortical tissues are limited internally by an 

endodermis, which is Seldom distinctly seen for any 

considerable distance, perhaps because of faulty preservation. In Tempskya knowltoni Seward it is not 

usually observed, but in one species that is described 

in this paper it is a fairly definite layer and is of the 

type found in the leptosporangiate Filicales.

The pericycle, which is developed below the endodermis, is a tissue of parenchymatous nature and variable thickness. It is usually thin (only two or three 

cells in thickness), although hi some individuals it 

seems to be slightly thicker. Its inner limit cannot be 

determined exactly, for in many specimens it cannot 

be definitely delimited from the phloem. Plate 34, 

figure 3, illustrates this feature fairly well.

The phloem is rather indefinite so far as its limits are 

concerned. Its morphologic identity cannot always 

be determined with exactitude, but one of the writers 

has observed the remains of poorly preserved sieve 

plates, so there seems to be no doubt that it actually 

exists as a well-organized tissue. There appears to be 

a thin zone of larger parenchymatous cells on the inner 

face of the phloem, which may possibly be regarded as 

ground parenchyma occupying a position between the 

phloem and xylem. This has not finally been determined but is quite within the range of probability.

The xylem ring, which is the most conspicuous feature of the stele, is from 5 to about 15 cells in thickness. 

For the sake of convenience, the xylem may be divided 

into an outer limiting region of very small elements and 

an inner region of larger elements. The outer limiting 

region of the xylem may be best described as problematical protoxylem. It may form a rather continuous 

layer, as is seen in plate 30, figure 1, or it may be somewhat scattered, as hi plate 34, figure 4. In the writers' 

opinion this zone must be regarded as an exarch protoxylem, and in Tempskya grandis the protoxylem may 

vary from exarch to slightly mesarch. They are 

unable, however, to produce any evidence of spiral or 

annular thickenings on the walls of the elements. 

Such a condition is not without parallel in the Leptosporangiateae—the Schizaeaceae, for instance, being 

without any typical protoxylem. Also it is stressed 

that the siliceous constitution of all of the material 

seems to be unfavorable to the preservation of such 

delicate structures as the thickenings on the walls of 

the protoxylem, even though they were originally 

present.

The inner region of the xylem presents nothing out 

of the ordinary. The tracheids are of the scalariform 

type so common hi the Filicales. One feature of note, 

which the writers stress in the specific differentiation
AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA 111

attempted in another part of this paper, is the variation 

in the amount of parenchyma diffused through the 

xylem. In Tempskya knowltoni Seward there is very 

little xylem parenchyma, but in one of the species 

collected from the Aspen shale of Wyoming parenchyma is abundant. This variation is seen at once by 

comparing plate 31, figures 1 and 2, with plate 34, 

figures 3 and 4.

The xylem ring is continuous except in the region 

immediately subtended by a departing leaf trace and 

varies little in thickness except at such points. A 

discussion of the origin of these lateral organs is given 

below.

Internal to the xylem there is present a thin layer of 

parenchymatous tissue limited by an inner endodermis. This parenchyma includes both phloem, 

pericycle, and the layer of thin-walled cells between the 

xylem and phloem and is in all respects similar to the 

comparable tissues that enclose the xylem.

The pith is sclerotic in all specimens. Just below 

the endodermis there may be in some places a narrow 

zone of parenchymatous tissue, but by far the greater 

portion of the central area is occupied by sclerenchymatous tissue quite similar to that found in the middle 

cortex.

Leaf trace.—The stelar ring is, except in the region 

where leaf traces are given off, rather regular in thickness. On the upper side of the stem there are, however, in almost every section, indications of departure 

or preparation for departure of one or more traces to 

the lateral appendages. The situation that exists at 

the point of origin of a trace is, first of all, a thinning of 

the xylem ring in the immediate vicinity of the portion 

that is destined to pass out. At the same time this 

portion of the stele tends to arch outward, approaching 

gradually the state shown in text figure 5, a, and in 

plate 31, figure 1. The xylem and other stelar tissues 

thin still more and at the same time bulge outward 

(text fig. 5, 6). It must be borne in mind that the 

leaves are two-ranked on the upper surface, and a plane 

of bilateral symmetry lies between the two rows of appendages. Gradually the stele is broken, first on the 

side nearest this plane of bilateral symmetry, as is 

shown in text figure 5, c, and also in plate 31, figure 2. 

Immediately the internal and external phloem as well 

as the other tissues enclosed by the endodermis pass 

around the free ends of the xylem and become continuous. At the same time there is established a connection between the sclerotic and parenchymatous tissues 

of the middle and inner cortex and the similar tissues 

of the pith. This is well shown in plate 31, figure 2, as 

well as in text figure 5, e. The hook-shaped xylem 

rapidly becomes more highly arched and finally detached inferiorly to assume a curved form similar to 

that shown in text figure 5, d. This trace consists of 

an inner and outer phloem, pericycle, and endodermis 

with a centrally disposed band of xylem. At first the

trace is rather broadly U-shaped with the extremities 

facing directly inward. Gradually as the trace traverses the cortex on its obliquely ascending course these 

extremities fold inward until the very characteristic 

form of the free petiole or phyllopodium is assumed. 

This is shown in plate 42, figures 1-3 and 5, and in text 

figure 5, d and e. The gap formed by the leaf trace is 

very short, closing up almost immediately after the 

superior terminus of the trace becomes free from the 

main stele. The course of the traces, as has been previously suggested, is nearly parallel to that of the 

stem, so that a section cut transversely across the stem 

is very nearly a transverse section of the leaf trace. In 

the outer portion of the cortex and in the free and nearly 

free petioles such sections indicate that the vascular 

strand flexes to pass outward more rapidly.

The course of the protoxylem is very difficult to 

follow because it is not well differentiated. According 

to the writers' understanding, the leaf bundle is triarchendarch. A careful study of numerous leaf traces has 

shown that on .the inner (concave) side of each lateral 

termination of the leaf trace there is a cluster of small 

cells which has all the aspects of protoxylem. A third 

lies at the bottom of the concavity.

The length of the internode varies considerably 

within the genus. Plate 29, figure 3, and plate 32, 

figures 2-5, convey some idea of the extremes.

Phyllopodium.—The term "phyllopodium" as here 

used refers to the axial system of those lateral appendages of the stem commonly referred to as leaves—that 

is, it applies to the petiole and rachis and the branches 

of those organs. In all except one of the species that 

have been studied only the bases of the phyllopodia are 

commonly present. This fact is rather noteworthy, and 

its full significance is discussed in the descriptions of 

species. Here it is sufficient to point out that usually 

an abscission layer was early developed and resulted 

in the occurrence of attached leaves only at the apex 

of the false stem. The exception is Tempskya minor, 

where rachides are common in the groundmass of the 

false stem. Serial sections of several specimens have 

shown that these are attached to the axes. Some of 

these stems have been penetrated by adventitious roots, 

an indication of old age. It therefore seems most likely 

that in this species the leaves were persistent for a considerable time.

The vascular system at the base of the phyllopodium 

is similar to that of the leaf trace. There is a progressive thinning and at the same time a lengthening of the 

xylem strand, so that at its actual emergence from the 

stem it is but one to three tracheids wide except at the 

swollen terminals and includes a rather large area of 

sclerotic cells within the arch. (See pi. 42, fig. 1.) The 

most striking feature, however, is the decidedly involute position of the terminal portions of the strand as 

seen in plate 42, figure 1. There is a tendency for 

these points to curl inward as the leaf trace approaches
112 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

the periphery of the stem. At the base of the phyllopodium this is very marked and simulates the completely closed, pseudoaxial stele of the petiole of 

Gleichenia pectinata.

The problematical parenchyma sheath, phloem, 

pericycle, and endodermis completely encircle the 

xylem. These tissues are similar to those that enclose 

the xylem in the main axis and so do not merit further 

discussion except to point out that they diminish in 

areal extent in the phyllopodium so as to retain appropriate proportions with the xylem.

Within the C-shaped stelar mass there is a parenchymatous sheath of slight extent bordering the endodermis and flanked inwardly by a mass of sclerenchyma 

similar to that observed in the pith of the stem. Both 

the parenchymatous sheath and the sclerenchymatous 

tissue are in direct connection with similar areas 

external to the vascular strand—that is, there is a 

similar zone of thin-celled tissue on the adaxial side of 

the stele in direct connection around the extremities 

of the vascular bundle, and external to this there is a 

hypodermal layer of considerable extent of sclerotic 

tissue also in connection with the similar tissue within 

the C. The whole mass is enclosed by a narrow zooe 

of parenchyma, usually showing poor preservation and 

limited by an epidermis equally poor in preservation.

Dermal emergences are occasionally preserved in the 

species described as Tempskya minor. These are unbranched hairs several cells long and but one cell wide. 

They are particularly abundant in the younger parts 

of the stems, as is shown in plate 39, figures 1 and 2. 

Similar appendages are seen in transverse section hi 

plate 38, figure 1. Apparently these dermal hairs are 

soon lost, as sections cut through mature stems show 

little indication of such organs. Of course, the 

remains of these hairs may become quickly obliterated 

because of their small size. Furthermore, a search 

for them is particularly difficult on account of the 

great quantity of heterogeneous materials that compose 

the false stem.

Root.—The adventitious roots that form the closely 

felted mat around the stems are without exception 

diarch. As seen in plate 29, figure 3, they vary considerably in size, probably in part because of their 

distance from the point of origin and in part because of 

the branching. The stele is rather large and consists 

of two to four centrally disposed large tracheids 

grouped in an irregular line at right angles to the plane 

of the protoxylem. Laterally the tracheids very 

rapidly decrease in size to the first-formed elements, 

which consist of two to three cells located at the poles. 

A thin zone of sheathing parenchyma encircles the 

xylem, becoming continuous with the pericycle at the 

protoxylem points. The protophloem is located principally in a plane at right angles to the protoxylem and 

is as poorly differentiated as similar tissue in the stems. 

The pericycle is well developed and shows no noteworthy differences from that in the stems. A welldefined endodermis delimits the stele, showing at some 

points poorly preserved Caspary bands on the radial 

walls.

The cortex consists of a parenchymatous inner layer 

followed by a thick zone of sclerenchyma. On the 

exterior of this zone there is seen, in well-preserved 

specimens, a layer of large-celled parenchyma. Usually 

this zone shows a marked tendency to become lacunar 

through the breaking down of some of the tissue. The 

situation is illustrated in plate 40. Sheathing this 

lacunar layer are smaller, thicker-walled cells of the 

subepidermis and epidermis. Not uncommonly in 

well-preserved masses of roots there may be observed 

remarkably well preserved root hairs, which are, like 

those of modern plants, simple outgrowths from the 

epidermis. They are remarkable in Tempskya only 

because of the perfection of preservation of these 

delicate structures. They may, in fact, be taken as 

evidence of extremely rapid silicification of the material.

As regards the origin of the root, the first indication 

of the development of such an organ is reflected in a 

slight outward bulge in the pericycle. The vascular 

elements appear to grow out at a variable angle until 

they reach the middle cortex, where the root flexes 

directly outward. At the same time there is developed 

on the xylem ring of the stem a small protuberance of 

tracheids which appear to unite gradually with those 

of the root.

Tempskya knowltoni Seward

Plate 28, figures 1-3; plate 29, figure 3; plate 30, figures 1, 2; 

plate 31, figures 1, 2; plate 32, figure 1; plate 42, figure 4; 

plate 43, figures 2, 3.

1924. Tempskya knowltoni Seward, Annals of Botany, vol. 38, 

no. 151, pp. 485-507, pis. 16, 17.

Gross aspect. —The type specimen of Tempskya 

knowltoni, which has been reported by Seward, is a 

slightly curved tapering specimen about 33 centimeters 

long. In cross section the false stem is oval, as shown 

in plate 28, figures 1 and 2, owing possibly to compression. At the larger and presumably distal end the 

greater diameter is about 6 centimeters; at the smaller 

and proximal end, 2 centimeters. The surface is 

considerably weathered and gives to the specimen a 

rather nondescript appearance not unlike that of a 

half-decayed fragment of a palm stem, inasmuch as 

the numerous roots simulate the scattered bundles of a 

monocotyledon. Thin slices cut from the specimen 

show a very excellent preservation. Plate 28, figures 

1 and 2, show the general aspect of T. knowltoni in 

transverse section. The stems, which are numerous, 

are sheathed in a dense felt of their own adventitious 

roots. It will be noted that several stems are cut at 

stages of dichotomy, which in this species was 

apparently equal.

Photographs of portions of thin sections of Tempskya 

knowltoni taken at a somewhat higher magnification
AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA 113

are shown in plate 28, figure 3, and plate 29, figure 3. 

The occurrence of the stems in the groundmass of roots 

is well shown. Most of the roots roughly parallel the 

stems in their course, but some of them deviate to run 

obliquely. One very characteristic feature of the 

siphonostelic stems is well brought out in these photographs—the very dense and thick sclerotic cortex. In 

both figures numerous roots invade the stelar tissues. 

This likewise is rather significant and is carefully 

considered on page 123.

Anatomy of the stem.—Plate 31, figure 1, illustrates 

the general aspect of the stem at a magnification of 

about 40 diameters. The division of the cortex into 

three distinct regions is clearly shown. On the outside 

is seen a large-celled parenchymatous tissue that shows 

a tendency to slough and shred. This zone is only a 

few cells thick. Within is a very thick zone of sclerenchyma that shows a dense black on the photograph. 

This region of fibrous tissue is exceptionally developed 

in Tempskya knowltoni and furnishes one criterion for 

its specific separation. The inner cortex is rarely well 

preserved in this species. It is, however, shown at 

points and is parenchymatous and from 6 to 11 cells in 

thickness.

The endodermis is poorly defined in the species, owing 

possibly to faulty preservation. At any rate it can* be 

recognized at only a few points but is probably a layer 

a single cell in thickness bounding the cortex. Within 

lie the pericycle, phloem, and sheathing parenchyma, 

all poorly preserved but definite at various points on 

most stems.

The xylem ring, as is shown in plate 30, figure 1, and 

plate 31, figures 1 and 2, is from 4 to 15 cells in thickness. It is composed almost entirely of scalariform 

tracheids with almost no xylem parenchyma. On the 

exterior of the ring there is an almost continuous layer 

of very small lumened tracheids. Superficially these 

suggest protoxylem and in fact are probably best 

regarded as such, despite the fact that they are scalariform rather than spiral. It may be assumed, temporarily at least, that the protoxylem is exarch and not 

well differentiated. Such a condition is not without 

parallel in extant ferns, among which the Schizaeaceae 

and some other Leptosporangiatae show a similar 

structure.

Within the xylem ring there is a repetition on a 

slightly smaller scale of the sheathing parenchyma, 

phloem, and pericycle investing the cylinder. This 

zone is bounded by an internal endodermis also vaguely 

marked.

The central area of the stem consists of an outer thinwalled zone, already described and similar to the inner 

cortex in general appearance and extent, which encloses 

an area of very thick-walled, small-lumened sclerenchymatous tissue.

Leaf trace.—The numerous sections of stems of 

Tempskya knowltoni furnish a very complete series of

stages bearing on the origin and development of the 

leaf trace. The first indication of an emerging strand 

destined to pass into a phyllopodium is a thinning of the 

whole stele in a small area in the upper half of the stem. 

The position of this point is usually to the side of the 

medial plane. Accompanying this decrease of a part 

of the stele there is a flexing outward of the area, as 

seen in plate 31, figure 1. This protrusion rapidly 

increases until first the xylem strand and finally the 

phloem, pericycle, and endodermis are interrupted on 

the upper side of the-bulge, as is shown in the stem to 

the left in plate 31, figure 2. The outer and inner 

phloem, pericycle, and endodermis immediately close 

around this interruption both on the side of the leaf 

trace and of the parent stele. The figures show that a 

portion of the pith passes outward within the inverted 

U-shaped meristele. Shortly after the parting of the 

termination of the trace on the upper side—that is, the 

one proximal to the median plane—the lower termination separates in a similar manner. The result is the 

formation of a broad and shallow U-shaped trace with 

the two ends facing inward toward the foliar gap (pi. 

31, fig. 2). This trace consists of a thin strand of xylem 

thickening toward the extremities, where the protoxylem appears to lie on the inner side. Phloem, pericycle, 

and endodermis completely enclose the xylem but 

form a thicker zone on the convex side of the U than, in 

the concavity. The mass of sclerenchymatous pith 

that followed the leaf trace out and occupied the space 

within the U becomes continuous with the similar 

tissue of the cortex as soon as the trace penetrates this 

tissue.

The course of the trace through the cortex is nearly 

parallel to the parent stele. During this gradual 

emergence there is a curving inward of the edges of 

the strand, as is shown in plate 30, figure 2. The 

xylem on the upper side of the trace thins to one or 

two tracheids in thickness, and the identity of the 

internal sclerenchyma is lost by reason of its similarity 

to that of the cortex, with which it is in direct connection.

Phyllopodium.—Very rarely are free leaf bases— 

phyllopodia—observed in the sections of Tempskya 

knowltoni Seward. Where they are present they are 

usually in an advanced stage of decomposition and disintegration, as attested by the clogging of lumens with 

dark gumlike deposits, maceration of cells, and dislocation of tissues. As a result, though the series of 

stages leading up to the phyllopodium is complete, 

the sum total of knowledge of the mature organ is 

very small. It is certain, however, that the single 

vascular strand of the leaf trace persists and is modified 

into the highly convoluted meristele described for the 

genus as a whole.

Roots.—The mass of the specimen is, as in other 

species, a mat of branching roots, which differs little 

within the genus. The xylem is diarch, with two or
114 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

three centrally located tracheids of unusually large 

diameter. The phloem and pericycle are well developed, 

and the stele is limited by an endodermal sheath. 

The cortex is similar to that of other species.

Comparison.—The only species of Tempskya, previously described that is well enough preserved to permit 

accurate comparison is Tempskya rossica Kidston and 

Gwynne-Vaughan. 19 It has been suggested that these 

species may be identical, the apparent differences being 

due to the derivation of the specimens from proximal 

and distal portions of the false trunk, respectively. 20 

In the writers' opinion these two species are distinct, 

although they admit that considerable variation may be 

expected in different parts of the same axis and between 

different individuals of the same species. The most 

obvious differences are as follows:

1. The size of the individual stems. According to 

the account given by Kidston and Gwynne-Vaughan, 

the stems of their species are much larger than those 

of Tempskya knowltoni.

2. The symmetry of the false stem. In Tempskya 

rossica the stems are arranged roughly according to a 

plan of radial symmetry. T. knowltoni shows a distinct dorsiventrality. This variation in the plan of 

symmetry is, in the writers' opinion, a character of 

some value.

3. The length of the internodes. In Tempskya 

knowltoni the internodes are of such length that only 

rarely does a trace remain in the cortex of the axis at 

the third node above the point where it originated. 

The figures of T. rossica indicate that the internodes 

were somewhat shorter in that species.

4. The nature of the xylem. The xylem of Tempskya knowltoni is homogeneous, but in T. rossica a 

considerable quantity of parenchyma is present.

Tempskya knowltoni Seward is quite distinct from 

the species described as new in this paper. Comparisons are presented elsewhere (pp. 116, 118).

Occurrence: Colorado shale (Upper Cretaceous), about 500 feet 

above base, about 10 miles southeast of Harlowton, Mont., in 

sec. 36, T. 7 N., R. 16 E. Collected in 1908 by A. C. Silberling.

Holotype: U. S. Nat, Mus. 39266.

Tempskya grandis Read and Brown, n. sp.

Plate 29, figure 2; plate 32, figures 2-5; plate 33, figures 1-4; 

plate 34, figures 1-4; plate 35, figures 1-4; plate 41, figure 4; 

plate 42, figures 1-3; plate 43, figures 1, 4-7

The collections of Tempskya made by W. W. Rubey 

and J. S. Williams in the Aspen shale of the Wyoming 

Range of western Wyoming include two very distinct 

species—one a small-stemmed form with long internodes and the other a large-stemmed form with 

crowded nodes. This large-stemmed form the writers 

propose to call Tempskya grandis.

is Kidston, Robert, and Gwynne-Vaughan, D. T., On a new species of Tempskya 

from Russia: Russ. k. min. Gesell. Verb., Band 48, pp. 1-20, pis. 1-3, 1911. 

!0 Seward, A. C., Annals of Botany, vol. 38, no. 151, p. 498, 1924.

Gross aspect.—The type specimen of Tempskya 

grandis is a columnar fragment of a false stem about 8 

centimeters in diameter and 20 centimeters long. The 

shape in cross section is oval, as is common in the false 

stems that have been examined. The weathered surface is quite like that of T. knowltoni Seward.

Plate 29, figure 2, illustrates the general aspect in 

cross section of Tempskya grandis at a low magnification. The stems are large as compared with T. 

knowltoni Seward and differ in several notable respects, 

as shown below. Text figure 3 (p. 108) is a carefully 

traced drawing of the false stem and the small stems 

included. The fact that these stems are dorsiventral 

shows clearly that there is a radial arrangement 

throughout so far as the orientation of these organs 

is concerned. Without exception the leaf traces that 

are sketched as U-shaped lines face toward the nearest 

point on the periphery of the mass. This arrangement 

of dorsiventral stems to simulate and probably to 

function in many respects as a single radially symmetrical axis is a very remarkable adaptation. The full 

significance of this feature is discussed on page 123.

Anatomy of the stem.—Plate 32, figures 2-5, illustrates the general appearance of typical stems of 

Tempskya grandis when slightly enlarged. The vascular cylinder is, of course, a siphonostele. Numerous 

leaf traces at various stages of development are visible.

The epidermis of the stem is rarely well enough preserved to be studied. Ordinarily the outermost tissueis a thin layer of parenchyma, indicated in plate 34,. 

figure 4. This tissue is what the writers have called 

the outer cortex. Commonly it is deeply stained with 

some dark gummy substance. Immediately beneath 

the outer parenchymatous cortex is a region of sclerenchyma that constitutes the middle cortex. This 

feature is also indicated in plate 34, figure 4. This? 

tissue is clearly very similar in histology to the comparable tissue in Tempskya knowltoni Seward but 

differs in its extent. A comparison of plate 31, figure 2 

(T. knowltoni}, with plate 34, figure 4 (T. grandis) f 

immediately indicates that in T. grandis the amount 

of middle cortex is much less in proportion to the size 

of the stem than in T. knowltoni.

Beneath the tissue just described is a very well 

developed inner cortex, shown in plate 34, figure 4. In 

Tempskya knowltoni the parenchymatous inner cortex 

is a tissue of slight extent and presents no especially 

noteworthy features. In T. grandis, however, a, 

somewhat different and significant condition is manifested. Plate 34, figures 2 and 4, shows that not only 

is this zone very well developed and fully as wide as 

that of the middle cortex but in addition there is 

an irregular band and commonly isolated nests of 

gummy sclerenchyma near the inner margin. Plate 

34, figures 1 and 4, illustrates a portion of the inner 

cortex at a medium magnification and gives a good
AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA 115

idea of the histology. The writers are inclined to 

accept this differentiation of the inner cortex as a 

character of specific value.

The endodermis in Tempskya grandis is usually 

rather definite. Beneath it lies a thin layer of pericycle, then phloem, and finally the sheathing parenchyma of the xylem. (See pi. 34, fig. 3.)

The cylinder of xylem is well developed and prominent. In detail it differs somewhat from that of 

Tempskya knowltoni Seward. Plate 33, figure 3, shows 

that the zone of small-lumened elements, which is so 

prominent in T. knowltoni on the periphery of the 

ring, is not so conspicuous in T. grandis. The writers 

examined over 100 cross sections of steles and in none 

of them found this region so well developed. The position of the protoxylem is problematic. It appears, 

however, that this may be exarch or very slightly 

immersed (see pi. 34, fig. 3) and limited to a very small 

amount. Another point of difference between T. 

knowltoni and T. grandis is the abundance of xylem 

parenchyma in T. grandis. Plate 31, figures 1 and 2, 

and plate 34, figures 3 and 4, show that abundant thinwalled elements are interspersed with the tracheids. 

These cells have all the outward aspects of parenchyma, 

and the writers can only interpret them as such. 

Similar xylem parenchyma occurs in most of the families 

of the Filicales.

In Tempskya grandis, as in T. knowltoni Seward, an 

inner phloem, pericycle, and endodermis are present, 

although these tissues do not form so extensive a 

zone as those on the exterior of the xylem.

The outermost tissues of the pith are extremely 

interesting for several reasons. Plate 34, figure 2, 

indicates that there exists just within the endodermis a 

zone of large-celled parenchyma containing nests of 

sclerenchyma, and these are particularly abundant in 

the vicinity of a leaf gap. As a comparable zone exists 

hi the cortex just outside of the outer endodermis 

the two may have a common origin. The writers do 

not propose to enter into the highly controversial discussion of the origin of the pith in the Filicales, because 

the several theories that have been advanced are 

subjects foreign to the purpose of this paper. Nevertheless, regardless of the origin of the tissues, they seem 

to furnish very reliable criteria for specific differentiation.

The central portion of the pith is an area of sclerenchymatous tissue similar to that found in Tempskya 

.knowltoni Seward. Plate 34, figure 2, illustrates the

•general aspect of this region.

Leaf trace.—The illustrations of Tempskya grandis 

show that every section contains several leaf traces at 

various stages of development. . A comparison of plate 

32, figures 2-5, with plate 29, figure 3, shows clearly 

that the traces in T. grandis are more numerous in any

•given portion of the stem than in T. knowltoni. Consequently it may be inferred that in the former the internode was much shorter than in the latter, as the writers 

believe, or else the traces passed outward at a more 

acute angle. This abundance of leaf traces has enabled 

the writers to make a very detailed study of the origin 

and development of the vascular strands that lead to 

the lateral organs.

A very early stage in the origin of a trace is shown in 

plate 35, figure 4 (on the left). At this point only a 

slight protrusion of the xylem strand and a narrowing in 

width are material evidence that the stele is about to 

be interrupted. A somewhat later stage is shown in 

plate 32, figure 3. The protrusion seen in plate 35, 

figure 4, has become plainly marked, and the stele is 

about to part at the point of formation of the upper 

termination of the trace. In plate 35, figures 3 and 4, 

this gap has appeared, and a very decided xylem loop 

has formed. Also a constriction of the stele at the 

point destined to be the lower termination of the trace 

is evident. These illustrations clearly show that a portion of the parenchymatous and sclerotic pith fills the 

concavity of the trace.

Plate 35, figures 3 and 4, shows the leaf trace shortly 

after the formation of a complete foliar gap. The trace 

consists of a narrow inverted U-shaped xylem strand, 

which is slightly swollen at the terminations and 

invested by phloem, pericycle, and endodermis. The 

concavity facing toward the parent stele contains a 

tissue that is histologically identical with the pith. An 

interesting feature is the development of a large amount 

of parenchymatous tissue containing nests and irregular 

patches of sclerenchyma in the region of the foliar gap. 

As previously stated, this tissue is characteristic both 

of the inner cortex and of the outer pith. There is a 

connection between these two usually separate units 

at the gap, and nests of sclerenchyma actually lie in 

the opening.

In plate 32, figure 5, the trace is shown in the sclerenchymatous cortex. Its general configuration is similar 

to that just described, but the terminations tend to 

curve inward. The investing tissues are very interesting. The characteristic parenchymatous and sclerotic 

tissue that sheathes the parent siphonostele both within 

and without occurs as a comparable sheath to the trace.

Plate 32, figure 3, illustrates a somewhat later stage 

in development of the trace. The ends are recurved, 

and it may be assumed that there is a progressive tendency toward this curvature, which has its extreme 

development at the base of the phyllopodium.

A very significant point, which the writers wish to 

emphasize, is the apparently short length of the internodes in Tempskya grandis as compared with T. 

knowltoni Seward. The numerous foliar traces that 

occur in every transverse section of a stem are highly 

indicative of such a condition. Likewise it is worth 

noting that almost invariably the sections of the central 

steles show foliar gaps. In contrast, T. knowltoni 

Seward shows not uncommonly a completely closed
116 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

stelar cylinder, and likewise the traces are never so 

numerous in any one section.

Phyllopodium.—In plate 42, figure 1, a phyllopodium 

of Tempskya grandis is shown in transverse section. 

The xylem strand is a modified, inverted U with the 

terminations swollen and strongly incurved. The dorsal convexity is flattened and tends to flex downward 

medially. Except for the terminations the xylem is 

rarely over two tracheids in thickness and commonly 

only one. The protoxylem, as in the solenostele, is 

problematical, for DO spiral or annular elements have 

been observed. From the size of the tracheids, however, it appears that there are three groups of endarcb 

protoxylem, one occupying the ventral surface of each 

of the swollen terminations and the third at the point of 

flattening of the medial portion of the strand. An 

endodermis completely encases the stele, following the 

contour of the xylem. A considerable amount of 

phloem exists externally but is clearly reduced internally.

The extrastelar tissues are extremely interesting. 

The exterior of the phyllopodium consists of a poorly 

preserved epidermis beneath which is a small amount 

of parenchyma. In some specimens this tissue is 

clearly reduced to isolated areas that contain only a 

few cells. The bulk of the outer mass consists of a 

thick zone of sclerenchymatous tissue, apparently 

homologous with the middle cortex of the stem. 

Within this sheath lies a broad tract of large-celled 

parenchyma containing an irregular zone and isolated 

patches of sclerenchyma. This tissue is similar to 

and probably histologically identical with the inner 

cortex of the stem. As shown in the illustration, the 

area is continuous with the similar area on the inside 

of the bay of the meristele. The central portion of 

the bay is occupied by a mass of sclerenchyma.

Root.—The root varies so little in the several species of 

Tempskya examined that the generic description may 

be taken as a general account. The stele is diarch and 

is limited by a readily distinguishable endodermis, and 

the cortex is almost entirely sclerenchymatous.

The roots branch freely and occur in a variety of 

sizes. So far as the writers have been able to ascertain they are essentially parallel to the course of the 

stems, although they may locally deviate considerably 

from the course.

Comparison.—Tempskya grandis stands so distinctly 

apart from the several other species of the genus which 

have been described that there can be no question of 

its validity. Probably its nearest relative, if the details of vegetative anatomy may be taken as a guide, 

is T. rossica Kidston and Gwynne-Vaughan, 21 from a 

Tertiary conglomerate in the Karaganda River Basin

2' Kidston, Robert, and Gwynne-Vaughan, D. T., On a new species of Tempskya 

from Russia: Russ. k. min. Gesell. Verb., Band 48, pp. 1-20, pis. 1-3, 1911.

of Russia. However, the specimen appears to have 

been reworked from older, probably Cretaceous rocks. 

According to Kidston and Gwynne-Vaughan this species 

is characterized by

stems 6-7 millimeters in diameter. Leaves very closely inserted, indications of two leaf traces being present in each transverse section of the stem. Vascular system a solenostele. 

Xylem parenchymatous, tracheae scalariform, rarely multiseriate, without definite protoxylem groups. Petiole about 5 

millimeters in greatest diameter. Leaf trace in petiole horseshoe-shaped with median abaxial depression and incurved, 

slightly enlarged extremities.22

According to this diagnosis Tempskya rossica approaches T. grandis in size of the stems and in the 

parenchymatous condition of the xylem. In fact, the 

writers were inclined during their preliminary studies 

to identify the species here described as new with the 

Russian specimen. A number of differences have 

manifested themselves, however, upon careful study. 

The internodes are much shorter in T. grandis, as is 

indicated both by the serial sections and by the numerous leaf traces (commonly five or six) found in every 

cross section of a stem. This, of course, cannot be 

taken as a criterion of high specific value but coupled 

with other evidence may be accepted with slight reservation. More significant is the matter of the inner 

cortex. Kidston and Gwynne-Vaughan found that in 

T. rossica

the cortex consists of two distinct zones; that next the stele 

is composed of fairly large cells with comparatively thin walls, 

probably parenchyma. Then comes a zone of thick-walled 

sclerenchyma about half as wide as the inner cortex, and outside 

this there may be a few layers of thin-walled cells.23

No mention is made of the occurrence of an irregular 

zone of sclerenchyma near the inner border of the inner 

cortex, and their figures do not indicate such a tissue. 

Such a zone, however, is invariably present in T. grandis 

and may be taken as a character of considerable systematic value. The similar outer pith found in T. 

grandis is also different from that in T. rossica, where 

"there is a zone of thin-walled parenchyma next the 

endodermis, while the whole of the central region of the 

stem is occupied by a mass of sclerotic cells." 34 The 

outer pith and inner cortex of the phyllopodium, which 

are histologically identical with comparable regions of 

the stem, differ in the same manner in T. grandis and 

T. rossica.

Numerous differences between Tempskya grandis 

and T. knowltoni Seward have already been pointed 

out. The longer internodes, the narrow zones of inner 

cortex and outer pith, which are entirely parenchymatous, the absence of any appreciable quantity of 

xylem parenchyma, and the flattened meristele of the 

phyllopodium in T. knowltoni Seward are characters 

that serve as accurate indices to its segregation.

M Idem, pp. 13-14. " Idem, p. 9. •* Idem, p. 10.
AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA 117

Also, if the single specimen of Tempskya knowltoni 

can be accepted as typical and entire, the dorsiventral 

symmetry of the false stem as contrasted with the radial 

symmetry of the aggregation in T. grandis may likewise furnish grounds for distinction. The writers are 

inclined to place some emphasis on this character in 

systematic work.

Occurrence: Material collected by W. W. Rubey ai d J. S. 

Williams in porcelainlike beds of Aspen shale (Upper Cretaceous) about 400 feet above the Bear River formation (Upper 

Cretaceous) at a locality in sec. 17, T. 35 N., R. 115 W., in the 

Afton quadrangle, Wyo. In addition one specimen was collected by S. H. Knight, of the University of Wyoming, from 

the Aspen shale in sec. 14, T. 31 N., R. 115 W., Lincoln County, 

Wyo., and transmitted to the writers by G. R. Wieland, of Yale 

University.

Cotypes: U. S. Nat. Mus. 39267, 39164.

Tempskya minor Read and Brown, n. sp.

Plate 29, figure 1; plate 36, figures 1-4; plate 37, figures 1-4; 

plate 38, figures 1-4; plate 39, figures 1-4; plate 40, figures 

1-4; plate 41, figures 1-3; plate 42, figure 5.

In addition to Tempskya grandis the collections 

made by Rubey and Williams in the Aspen shale 

(Upper Cretaceous) contain a small-stemmed species of 

the same genus. Similar specimens are included in the 

small lot obtained from the Wayan formation of southeastern Idaho by Mansfield in 1930 and by Mansfield, 

Rubey, and Williams in 1931 and S. H. Knight from 

the Aspen shale in sec. 14, T. 31 N., R. 115.W., Lincoln County, Wyo. This species is of the same general 

stock as Tempskya knowltoni Seward; in fact, the relationship seems to be very close. The writers believe, 

however, that Tempskya minor is distinct and can, with 

care, be separated from T. knowltoni. Certain minor 

morphologic differences exist, and these appear to be 

constant. This separation may seem to some students 

to be of doubtful validity, but a careful study of the 

numerous figures should convince the observer that 

specific differences exist.

Gross aspect.—A sketch of a large transverse section 

of an entire false stem is shown in text figure 4 (p. 108). 

Only the outlines of the stems, leaf bases, and the 

steles of these organs have been drawn. A comparison 

with the sketch of Tempskya grandis shown in text 

figure 3 (p. 108) immediately indicates significant differences. With very few exceptions the stems are so 

oriented that their leaf bases face in one direction. In 

other words, the symmetry tends to be dorsiventral. 

Whether this is apparent or real it is impossible to say. 

Most of the specimens of this species are large and do 

not suggest mere segments of a much larger false stem. 

At present the writers prefer to regard the symmetry 

as real, although they admit the possibility that the 

dorsiventrality is only apparent.

In this respect Tempskya minor is similar to T. 

knowltoni. If the symmetry of T. minor and T. 

knowltoni is actually dorsiventral then there is a strong

suggestion of two groups of Tempskyas—one typified 

by T. minor and the other by the radially symmetrical 

T. grandis. These problematic subgeneric groups 

are discussed more fully on page 122.

Anatomy of the stem.—The general appearance of 

the stem of Tempskya minor is shown in plate 29, 

figure 1, and in plate 36, figures 1-4. The species 

conforms very well to the generic characters. The 

vascular tissues are arranged in a dorsiventral siphonostele. The leaf gaps are short, and the traces are 

inverted U-shaped. The cortex and pith contain 

prominent areas of sclerenchyma. A thick mass of 

adventitious roots sheaths each stem and binds the 

whole system into a false stem.

Plate 38, figure 3, illustrates outer tissues of a stem. 

The exterior is rarely well preserved but appears to 

consist of a few layers of large, thin-walled elements 

beneath the epidermis.

The middle cortex is an extensive area of sclerotic 

elements. In general this tissue is similar to that 

described in the cortex of Tempskya knowltoni Seward 

and T. grandis. However, it is not so highly sclerotized 

as in the other two species and does not form so thick 

a ring as in T. knowltoni.

The inner cortex is well developed. In proportion 

to the size of the stem the area occupied by this tissue 

is fully as broad as in Tempskya grandis. The elements are large and thin walled. The occurrence of 

nests or even isolated cells of sclerenchyma was not 

noted, in contrast with their universal occurrence in 

T. grandis, which was collected in the same beds.

The cortical tissues are limited by a distinct endodermis, which, however, is well preserved in only a few 

specimens. An inner as well as an outer endodermis 

is present. As in the other species described these 

become continuous at each foliar gap, closing around 

the free ends of the interrupted vascular cylinder.

In plate 41, figure 3, the details of the morphology 

of the stele are shown. The amount of tissue that 

can be identified with certainty as pericyclic is slight, 

much less than in either Tempskya knowltoni or T. 

grandis. Likewise the phloem and the sheathing 

parenchyma are reduced in amount, on both the 

exterior and the interior of the xylem.

The xylem ring is similar to that described for 

Tempskya knowltoni. In plate 39, figures 2 and 3, the 

details of structure of this tissue are shown at a rather 

high magnification. The nearly continuous peripheral 

zone of small elements that has been tentatively 

regarded as protoxylem in T. knowltoni is represented 

by a discontinuous zone in T. minor. Likewise the 

ring is somewhat narrower in T. minor. The xylem 

appears to be wholly without parenchyma, another 

point of difference from T. knowltoni, in which xylem 

parenchyma occurs in very small quantity, though it is 

present in most sections.
118 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

Within the inner endodermis there is a narrow zone 

of large-celled parenchyma enclosing a mass of sclerenchyma that extends to the center.

Leaf trace.—The stems of Tempskya minor are 

characterized by long internodes in comparison with 

the other species of Tempskya that have been studied. 

In consequence it is by no means uncommon to find 

transverse sections that show a continuous vascular 

cylinder and no sign of foliar interruption. (See pi. 

41, fig. 3.)

The first indication of the emission of a trace is a 

thinning of the xylem in the portion of the cylinder that 

is destined to pass into the rachis. At the same time 

there is a protrusion of the entire stele, which continues 

until a gap is formed on the upper side of the trace. 

The shape of the foliar strand then is that of a narrow, 

inverted U. Immediately afterward the lower termination of the strand is detached. The phloem, pericycle, and endodermis are continuous around the ends 

of the xylem, both in the parent stele and in the leaf 

trace. The gap is rather short and closes very soon 

after the departure of the trace.

In plate 37, figure 2, the aspect of the trace is shown 

shortly after its departure from the cylinder. It is a 

broad, shallow arch, obliquely ascending, with the 

xylem only 1 to 3 tracheids in thickness except at the 

swollen ends. Completely surrounding it is a thin 

layer of phloem, pericycle, and endodermis. Within 

this horseshoe-shaped mass is a narrow zone of parenchyma that partly encloses the sclerotic tissue, which 

is in connection with the sclerenchyma of the pith and 

unquestionably falls in the same morphologic category.

As the trace passes out through the cortex it becomes 

sheathed on its abaxial surface first with parenchyma 

and then with sclerenchyma from the middle cortex. 

Plate 37, figures 1-4, shows a series of stages in the 

development of the trace within the cortex. The stele 

is at first a broad, shallow U with slightly enlarged 

ends, which becomes progressively more and more 

recurved as the trace passes out. At the same time 

a slight depression develops on the abaxial surface.

The protoxylem groups are as problematical in the 

foliar trace as in the central cylinder. Groups of small 

tracheids that are tentatively regarded as protoxylem 

occur at the inner surface of the enlarged terminations 

and at the centrally located depression of the stele. 

Though no indication of spiral or annular thickenings 

has been observed, it seems safe to assume that the 

traces are triarch-endarch.

Phyllopodium.—In plate 36, figure 1, the appearance 

of the rachis in transverse section shortly before it becomes completely detached is shown. The stele is a 

broad, flat arch with recurved and enlarged terminations. Near the center there is the prominent abaxial 

depression that has already been mentioned. The 

protoxylem is apparently triarch and endarch. Completely enclosing the xylem strand is a zone of phloem,

pericycle, and endodermis, which follows the configuration of the xylem very exactly. Within the arch there 

is a thin layer of parenchyma, which is continuous with 

a smaller tissue on the outer surface of the stele. The 

center is a mass of sclerotic tissue likewise in connection 

with the similar layer on the exterior, which makes up 

the bulk of the rachis, as is clearly shown in the figure.

Numerous remains of rachides are found in the 

groundmass of roots. These are scarcely well enough 

preserved to warrant description. Generally the stele 

is decayed or reduced to an unidentifiable mass and 

commonly displaced. Two of these masses are illustrated in plate 42, figure 5. This common occurrence,of 

rachides in the root felt of Tempskya minor is in decided 

contrast with the condition in T. knowltoni, where such 

organs are very rare.

Root.—No essential difference in root structure 

between Tempskya minor and T. knowltoni and T. 

grandis was observed. Therefore the details of structure of these organs need not be considered. In fact, 

the generic description suffices for all the species that 

are considered in this report.

Comparison.—The foregoing description clearly indicates that Tempskya minor is very distinct from its 

associate in the Aspen shale, T. grandis. To recapitulate: T. grandis is a large-stemmed species with very 

short internodes. The axis is characterized by a 

xylem containing abundant parenchyma and by an 

inner parenchymatous cortex of considerable extent 

containing an irregular zone of sclerotic cells. A 

similar tissue exists in the outer pith. The rachis 

contains a deep, highly recurved stelar arch surrounded 

by tissues similar to those in the stem. On the other 

hand, T. minor is a small-stemmed form with a homogeneous xylem and without fibrous masses in the inner 

cortex. The foliar meristele is a flat arch, not nearly 

so recurved at the ends. The internodes are very long. 

The false stehi of T. grandis is radially symmetrical; 

that of T. minor is approximately dorsiventral. The 

differences are so numerous and so constant that there 

is little danger of confusing the two.

The distinction of Tempskya minor from T. knowltoni 

is much more finely drawn, yet the writers believe that 

the two species can be accurately separated if sufficient 

care is taken. The more noteworthy differences are 

the larger size of T. minor, the more compact xylem with 

groups of problematic protoxylem instead of a nearly 

continuous layer, the broader zone of inner cortex, the 

less sclerotic outer cortex, and the broader, flatter 

arch of the meristele in the base of the rachis. In T. 

knowltoni the xylem contains some parenchyma; in T. 

minor such cells have not been observed. Likewise it 

appears that in T. minor the leaves, as indicated by the 

common occurrence of rachides, were more persistent 

than in T. knowltoni, where such organs are very rare.

Of the European species Tempskya rossica is the 

only one well enough known to justify comparison.
AMERICAN CRETACEOUS FERNS OP THE GENUS TEMPSKYA 119

This species, however, is closely related to T. grandis 

and in consequence should not be confused with the 

plant here described. According to the original 

report,25 T. rossica is characterized by short intern odes 

and in consequence numerous foliar traces in cross 

section and by xylem parenchyma. The stems are 

very nearly the size of the larger ones in T. minor. 

However, microscopic examination should make the 

separation rather simple, for T. minor contains no 

xylem parenchyma.

Occurrence: 1. Porcelainlike beds of Aspen shale about 400 

feet above the Bear River formation in sec. 17, T. 35 N., R. 115 

W., Wyo. Collected in 1931 by W. W. Rubey and J. S. Williams.

2. Aspen shale in sec. 14, T. 31 N., R. 115 W., Lincoln County, 

Wyo. Collected by S. H. Knight and transmitted by G. R. 

Wieland.

3. Aspen shale on divide between middle and east forks of 

Hoback Creek near head, in sec. 18, T. 35 N., R. 115 W., Wyo. 

Collected in 1931 by W. W. Rubey and J. S. Williams. Another collection from this same locality was made by W. W. 

Rubey in 1933.

4. Terrace gravel in valley of Twin Creek near Fossil, Wyo. 

Collected by R. W. Brown in 1930.

5. Upper part of Wayan formation in sees. 17 and 19, T. 5 S., 

R. 44 E., Idaho. Collected by G. R. Mansfield.

Cotypes: U. S. Nat. Mus. 39253, 39259, 39260; paratypes: 

U. S. Nat. Mus. 39163, 39254, 39255, 39256, 39257, 39258, 39261, 

39262.

Tempskya whitei Berry

1911. Berry, E. W., Maryland Geol. Survey, Lower Cretaceous, 

pp. 295-299, pis. 37, 38.

The specimens designated Tempskya whitei by 

Berry in his report on the Lower Cretaceous floras of 

Maryland have considerable historic interest. They 

represent the first record of the genus in America and 

also the only one from the Atlantic Coastal Plain. In 

consequence the writers have devoted much more time 

to the study of the prepared sections than the very 

poor preservation would really warrant. The results 

have been rather unsatisfactory, as will be seen below.

Tempskya whitei Berry is a large-stemmed form 

with relatively short internodes, as is indicated by the 

numerous leaf bases. In most specimens it has been 

impossible to observe the details of the xylem ring, 

but in a few of the best-preserved stems it appears 

to be from 7 to 12 tracheids in thickness and very 

sparingly parenchymatous. The protoxylem is in its 

usual position on the exterior of the cylinder. The 

cortex and "pith" are so poorly preserved in all the 

sections that their detailed structure cannot be determined. The leaf traces are apparently similar in form 

to those of the other species described in this paper.

The above remarks are intended to justify the writers' 

opinion as to the validity of the generic determination 

of this material. The very poor state of preservation 

makes it impossible to formulate a specific diagnosis 

at this time.

28 Kidston, Robert, and Gwynne-Vaughan, D. T., op. cit., 1911. 

75417—37———2

Occurrence: Patapsco formation (Lower Cretaceous). The 

specimens examined by the writers came from Stony Run 

and Deep Run near Severn, Anne Arundel County, Md.

Plesiotype: U. S. Nat. Mus. 39264.

Tempskya sp.

A small fragment of a large false trunk of Tempskya 

from the La Sal Mountains of Utah has come to the 

writers through the kindness of Frank L. Hess, of the 

United States Bureau of Mines. This specimen is, 

unfortunately, a mass of diarch roots without any 

recognizable stems. In consequence it is impossible to 

assign the material to any species, as the roots do not 

afford any specific criteria. The record is of value 

only in that it further outlines the geographic and 

stratigraphic distribution of the genus.

Occurrence: Collected by F. L. Hess in the La Sal Mountains, 

Utah, on the divide southwest of Winburn's ranch, near the 

head and northwest of Pack Creek; probably from the Upper 

Cretaceous Dakota (?) sandstone.

Holotype: U. S. Nat. Mus. 39265.

SYNOPSIS

The writers have prepared a concise synopsis of the 

chief characters that serve to segregate the several 

better-known species of Tempskya. This synopsis 

may be of value not only for general reference but also 

for aid in identification.

1. Individual stems of false stem large, with very short internodes as indicated by the numerous leaf bases present in 

transverse sections. Xylem exarch or possibly slightly 

immersed in some specimens. False stem chiefly radially 

symmetrical. Xylem ring containing much parenchyma:26 

A. Inner cortex a broad zone of parenchyma containing near its inner margin an irregular but continuous tract of sclerenchyma. Outer layer of 

"pith" a similar zone of parenchyma containing 

sclerenchyma, especially in the vicinity of the 

nodes.____________________ Tempskya grandis.

B. Inner cortex a narrow zone of large-celled parenchyma. Presence of an inner sclerotic layer not 

recorded.___-_____--___--__ Tempskya rossica.

2. Individual stems of false stem small, internodes of such length 

as to permit only a little overlapping (2-3) of leaf bases. 

Xylem exarch. False stem dorsiventral. Xylem ring 

containing little if any parenchyma: 27

A. Xylem very compact; protoxylem commonly segregated into definite groups. Inner cortex broad, 

parenchymatous. Petioles common in false 

stems, indicating persistence of leaves; xylem arch 

fairly flat. Stems averaging larger than those 

in the next group_____________ Tempskya minor.

B. Xylem compact but with parenchyma in places 

interspersed with the tracheids. Inner cortex 

usually narrow, parenchymatous. Petioles rare 

in false stem; xylem arch rounded.

Tempskya knowltoni.

29 Under 1 may probably be included such indifferently preserved and poorly 

known species as Tempskya whitei, T. erosa (some forms), T. pulchra, T. macrocaula, 

T. microrrhiza, and T. schimperi.

*' Some forms of Tempskya erosa belong in this group.
120 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

TAXONOMIC POSITION

AFFINITIES OF TEMPSKYA

In their admirable discussion of Tempskya rossica 

Kidston and Gwynne-Vaughan stated that

The affinities of the Tempskyas appear to lie with the leptosporangiate ferns, but beyond this their systematic positior must 

.*, &t present be left uncertain. * * * For instance, stems with 

a solenostelic vascular system are known to occur in the Schizaeaceae, Gleicheniaceae, the Dipteris-Matonia series, in Loxsoma, 

the Cyatheae, the Dennstaedtineae, and in certain series of the 

Polypodiaceae. 28

Even with the discovery of abundant new material 

these statements, though conservative, must still be 

accepted as expressive of the somewhat nebulous ideas 

concerning the affinities of Tempskya.

The writers have made a careful survey of the literature dealing with the vascular anatomy of the ferns in 

the hope that it would be possible to establish the systematic position of the genus. The results, though not 

so satisfactory as might be wished, narrow down the 

probable affinities somewhat and are therefore recorded.

The Eusporangiatae, as already stated, may at once 

be eliminated. The stems of the representatives of 

this group, both living and fossil so far as they are 

known, are quite distinct in their vascular make-up 

from those of Tempskya. Likewise there is the circumstantial evidence of the occurrence of sporangia of 

the leptosporangiate type entangled in the adventitious 

roots of Tempskya knowltoni.39

Although within the Leptosporangiatae siphonostelic axes occur in groups that appear to be widely 

separated, yet there are certain characteristic features 

of Tempskya that immediately tend to eliminate several possibilities. The probable absence of spiral 

protoxylem, the exarch or very slightly immersed position of the protoxylem, the shape of the leaf trace and 

its mode of origin, and the outline of the vascular system of the petiole are criteria of great value in narrowing down the affinities. Without going into detail 

regarding the morphologic discrepancies that have 

permitted this elimination, it may be stated that certain 

members of the Schizaeaceae, Loxsomaceae, and Gleicheniaceae are anatomically more harmonious with 

Tempskya than any other ferns of which the writers 

have seen accounts. These families present features, 

however, that apparently do not conform with those 

observed in Tempskya.

The Schizaeaceae are a family that includes four living genera—Schizaea, Lygodium, Aneimia, and Mohria. 

Except for the last-named, all the genera include 

numerous species. The distribution is widespread but 

chiefly tropical. In habit there is a pronounced tendency toward dorsiventrality, although the radial con-

* Kidston, Robert, and Gwynr e-Vaughan, D. T., On a new specite of Tempskya 

from Russia: Russ. k. min. Gesell. Verb., Band 48, pp. 16-17,1911. 

»» Seward, A. C. Annals of Botany, vol. 38, no. 151, p. 4S6, pi. 16, figs. 5, 8,1924.

dition persists in some species of Schizaea and Mohria 

and in most species of Aneimia. Repeated dichotomy 

of the stem characterizes all the dorsiventral representatives.

In the internal structure of the axis there is considerable diversity in the family, ranging from protostely to siphonostely and dictyostely. Among the 

siphonostelic members are encountered features that 

indicate an affinity with Tempskya.

The section Aneimiorrhiza of Aneimia forms a natural 

group of at least seven species, all having siphonostelic 

stems. Boodle 30 has published an authoritative treatise 

on the anatomical features of these species and of 

Aneimia mexicana in particular. The stems are highly 

sclerotic and show a thin ring of xylem bounded without 

and within by phloem, pericycle, and endodermis. 

The protoxylem is usually scalariform and appears 

diffuse exarch, although this point is not made clear. 

In some species, however, the spiral elements of the 

protoxylem in the leaf trace may continue downward 

into the central axis for a short distance. The petiole 

of this species has not been studied in detail, but in 

the related Aneimia aurita an inverted narrowly Ushaped leaf trace passes out in a manner similar to that 

in Tempskya. A median and two lateral areas of protoxylems are present. The phloem and endodermis 

conform to the outline of the xylem but are absent in 

the deeper portions of the concavity. The protoxylem 

is confined to the inner surface. A hypodermal layer 

of sclerenchyma is present, but the petiole is not prevailingly sclerotic.

The xylem presents certain features that militate 

somewhat against a very close comparison with 

Tempskya. According to Boodle, parenchyma intermingled with the tracheids is rare. If comparisons 

were being drawn only between this family and species 

of the type of Tempskya knowltoni Seward the point 

might be made that the occurrence of parenchyma is 

too sporadic to be worthy of serious consideration. 

However, its abundance in Tempskya rossica Kidston 

and Gwynne-Vaughan and in Tempskya grandis makes 

the difference worthy of note. Another feature upon 

which Boodle lays particular stress is the occurrence 

of sclerosed sieve tubes in the phloem of representatives 

of all the genera except Mohria. Such fibers have not 

been observed by the writers in Tempskya, nor has any 

record of such an occurrence been brought to their 

attention.

Another character that may be of some value in 

discussing the affinities of Tempskya is the prevalence 

of diarch roots in the Schizaeaceae similar to those 

characteristic of the fossil.

The Gleicheniaceae include two genera—the monotypic Stromatopteris and Gleichenia—with about 80

30 Boodle, L. A., Comparative anatomy of the Hymenophyllaceae, Schizaeaceae , 

and Gleicheniaceae; II, On the anatomy of the Schizaeaceae: Annals of Botany, 

vol. 15, pp. 359-421, pis. 19-21, 1901.
AMEEICAN CRETACEOUS PERNS OP THE GENUS TEMPSKYA 121

species. Their distribution is chiefly tropical and south 

temperate. Gleichenia has been divided into three 

subgenera—Mertensia, Eu-Gleichenia, and Platysoma. 

In species of Mertensia characters are seen that suggest 

a comparison with Tempskya. In most species of the 

genus a protostele characterizes the vascular axis, but 

in Gleichenia pectinata of the subgenus Mertensia there 

is a very interesting solenostele of a type highly suggestive of that in Tempskya.

In Gleichenia pectinata the stem is sclerotic. The 

solenostele carries numerous groups of slightly immersed protoxylem. Outer and inner phloem, pericycle, and endodermis are present. The central area 

is occupied by sclerenchyma. The stem is markedly 

dorsiventral, giving .off leaves above and roots below. 

At the node a band of tissue destined to pass into the 

leaf begins to separate from the xylem ring, the outer 

portion contributing more than the inner, in such a 

manner that the central sclerotic mass has a two-armed 

upward and lateral extension filling the concavity of 

the trace. The strand then splits off and gradually 

assumes an inverted U-shape with strongly recurved 

and somewhat swollen ends. The stele is left open for 

a time after the departure of the trace, so that there is 

free communication between central and cortical tissues.

In the petiole there is a prominent protoxylem group 

at each of the terminal hooks, and between lie an indeterminate number of groups derived from a centrally 

located protoxylem in the early stages of the leaf trace. 

A considerable amount of sclerenchyma is included in 

the convexity of the petiole, and the phloem and endodermis are continuous within as well as without the 

xylem.

In this plant there are several points of disagreement 

with the observed facts of structure in Tempskya, chief 

among which are the definite and slightly mesarch 

protoxylem, which is spiral, and the mode of origin of 

the leaf trace.

Evidence of spiral protoxylem has not been noted in 

Tempskya, and its presence in slightly mesarch groups 

in Gleichenia pectinata is a significant point of difference. 

However, such protoxylem may exist in Tempskya but 

may have been obliterated during the course of silicification. This feature is in the writers' opinion an 

indecisive one.

The origin of the leaf trace plainly presents considerable differences between Gleichenia pectinata and 

Tempskya species. However, some question may be 

raised as to the systematic value of this feature.

Certain characters of the xylem necessitate the 

careful consideration of the Gleicheniaceae in this 

discussion. In its parenchymatous nature the ring is 

strongly suggestive of the stele of Tempskyas of the 

group of Tempskya rossica. Likewise the outline of 

the petiolar bundle and the distribution of the tissues 

in general in Gleichenia pectinata as well as in other 

species of the genus is strongly suggestive of Tempskya.

The Loxsomaceae, a family of ferns of the Tropics 

and the Southern Hemisphere, include two genera— 

Loxsoma and Loxsomopsis, the former being monotypic. 

The anatomy of Loxsoma cunninghami has been fully 

investigated by Gwynne-Vaughan,31 and it is therefore 

possible to draw a rather careful comparison with 

Tempskya. The stem is; a typical solenostele, a complete ring of xylem being invested on both sides by 

phloem, pericycle, and endodermis. The groundmass 

of the stem is chiefly sclerenchyma, although a thin 

layer of parenchyma adjacent to the inner and outer 

endodermis is similar to the feature that the writers 

have called the inner cortex. Scattered "islets" of 

parenchyma occur in sclerotic tissue of the groundmass, being abundant in the vicinity of the stele and 

disappearing farther away. The xylem is only a few 

cells thick and may be parenchymatous. "The 

protoxylem * * * consists of narrow scalariform 

tracheids evenly distributed around the external 

periphery of the xylem ring." 32

The closed stele is interrupted periodically along the 

upper side by the departure of leaves. At each node 

a portion of the ring separates and passes slowly outward as an inverted U-»haped meristele. Through the 

gap thus formed in the central cylinder there is free 

communication of medullary and cortical tissues. This 

gap may continue for some distance but never overlaps 

the succeeding one.

The vascular strand in the petiole thus developed is 

horseshoe- or hi verted U-shaped, with the extremities 

enlarged and incurved. The protoxylem lies in several 

groups on the adaxial surface of the thin strand, one 

group occupying the bay of each of the incurved hooks 

and an indeterminate number being situated along the 

dorsal curve. The phloem, pericycle, and endodermis 

follow closely the contour of the xylem, although they 

may thin along the convex surface. The groundmass 

of the petiole is sclerer.chymatous in the proximal portions but becomes more parenchymatous higher up. 

The roots are diarch and similar to those in Tempskya.

Loxsoma cunninghami presents a number of features 

that suggest comparison with Tempskya. The exarch 

siphonostele with scalariform protoxylem, the sclerotic 

cortex, the dorsiventrality of the stem, the modified 

triarch, endarch leaf traces, and the diarch roots are 

all characters that arc, shared with Tempskya. However, the leaves are very nearly one-ranked, instead of 

two-ranked as in Tempskya, and the leaf trace is 

broader and flatter in outline. In Loxsoma islets of 

parenchyma related to the inner cortex are scattered 

in the sclerotic tissue for some distance from the stele, 

whereas in Tempskya grandis there are numerous islets 

and in fact an irregular sheet of sclerenchyma near the 

inner margin of the inner cortex. This feature may

» Qwynne-Vaughan, D. T., Observations on the anatomy of solenostelic ferns; 

I. Loxsoma: Annals of Botany, vol. 15, pp. 71-98, pi. 3,1901. 

38 Idem, p. 79.
122 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

be taken as evidence of a trend toward sclerification of 

the parenchymatous cortex, with the possibility not 

remote of isolation of the softer tissue as islands. It is, 

of course, impossible to say how far this sclerification 

proceeded.

The above discussion shows that the writers are at 

a loss regarding the exact affinities of Tempskya. 

Professor Seward has urged that the genus be referred 

to the Schizaeaceae and has drawn a close comparison 

with Aneimia.33 The writers admit that there is much 

to be said in favor of this reference, including the circumstantial occurrence of spores and sporangia in the 

root felt, but on the other hand there are several 

serious discrepancies. Therefore it is proposed to 

erect, temporarily at least, a group designation for 

Tempskya and related fossil forms. For this group the 

family name Tempskyaceae is suggested. The limits 

of this family must for the present remain in doubt, and 

it may be temporarily regarded as unigeneric.

To recapitulate, the Tempskyaceae are a family of 

Mesozoic ferns including one genus, Tempskya. Several species are known. The affinities of the group lie 

with the leptosporangiate ferns, and trends are seen 

that suggest relation with the Schizaeaceae and the 

Loxsomaceae on the one hand and the Gleicheniaceae 

on the other. The limits of the family cannot be 

determined at present.

INTERRELATIONSHIPS OF THE SPECIES

The problem of the relationships of the species of 

any genus is invariably difficult—in fact, several solutions can usually be found that will be in harmony 

with the apparent trends of phylesis. The writers' 

views presented here are merely suggestions and are by 

no means intended to be dogmatic.

In the more formal systematic portions of this paper 

evidence has been presented which clearly shows that 

the genus Tempskya can be divided into two natural 

groups. Tempskya knowltoni Seward may be taken 

as the type example of one group. It is a smallstemmed form with relatively long internodes, thick 

sclerotic cortex, and xylem that is homogeneous. 

T. grandis may be taken as the type of the other 

group. It is a large-stemmed type with very short 

internodes, parenchymatous xylem, and a cortex differentiated into several layers.

To the first group the writers assign Tempskya minor 

in addition to T. knowltoni. To the second are 

referred T. grandis, T. rossica Kidston and GwynneVaughan, T. whitei Berry, some specimens of T. erosa 

Mantell, and probably the several species described by 

Corda.

The relative primitiveness of the two groups is of 

great interest. Unfortunately, as at present known 

their stratigraphic ranges are approximately the same. 

3t appears that the group of Tempskya knowltoni is

33 Seward, A. C., Annals of Botany, vol. 38, no. 151, p. 499,1924.

more primitive so far as the morphology of the axis is 

concerned, and at the same time T. grandis presents 

several features that point to high specialization. The 

facts concerning this alleged primitiveness of T. 

knowltoni Seward may be summarized as follows:

The small stems with fairly long internodes seem 

more nearly typical of the solenostelic condition than 

the large stems with very short internodes that are 

exhibited in Tempskya grandis. In T. grandis it is at 

once evident that there is an approach to polystely and 

ventilation brought about by shortening of the internodal length, and as polystely, or any approach to it 

from the typical solenostele, is a distinct anatomical 

advance in the ferns it must be assumed that T. grandis 

is a more specialized representative of the genus.

The homogeneity of the xylem in Tempskya knowltoni may be taken as primitive, whereas the presence 

of abundant xylem parenchyma intermingled with the 

tracheids in T. grandis is some proof of advancement.

The cortex of Tempskya knowltoni is nearly homogeneous, consisting below the thin subepidermal zone 

of a broad belt of sclerotic tissue with only a few cells 

of parenchyma lying next to the endodermis. On the 

other hand, T. grandis has a cortex clearly divisible, 

below the subepidermal layers, into two zones—an 

outer sclerotic and a broad inner layer of parenchyma 

containing an irregular belt of sclerenchyma near 

its inner margin. It may be that the condition in T. 

knowltoni is primitive, or possibly it is a derivative of 

the condition in T. grandis.

There is indication that Tempskya knowltoni and 

others of the group present a dorsiventral symmetry 

in the false stem. T. grandis shows a distinct radial 

arrangement. It is reasonable to suppose that this 

dorsiventral condition preceded the radial one. This 

point is discussed above.

PROBABLE HABIT OF TEMPSKYA

The false stem, which is so characteristic of Tempskya, has been a subject of some discussion among 

paleobotanists because it brings up the very interesting problem of habit. A number of opinions on 

this point have already been considered in this paper, 

but for the sake of clarity it is necessary to restate 

briefly the conclusions of Kidston and GwynneVaughan and of Seward.

The aggregate of axes with their root packing must have 

stood upright. If they had grown horizontally the roots would 

not have run parallel with the stems, and again the leaf-bearing 

sides of all the stems would have pointed in the same direction— 

that is, away from the soil. The whole aggregate of axes and 

roots undoubtedly reached a very considerable height and size, 

for Fitton describes specimens of the fossil measuring as much 

as 9 feet long, 1 foot wide, and 4 inches thick. 34

An examination of the American material leads me to express 

an opinion different from that of Kidston and Gwynne-Vaughan. 

* * * The general though not invariable tendency of the

3* Kidston, Robert, and Qwynne-Vaughan, D. T., On a new species of Tempskya 

from Russia: Russ. k. min. Qesell. Verb., Band 48, p. 14,1911.
AMEEICAN CEETACEOUS FEENS OF THE GENUS TEMPSKYA 123

roots to follow a vertical course does not * * * justify the 

assumption of an erect position. The mass of compact roots 

seen in the fossil was probably covered during life by a much 

looser felt of roots which grew into the soil * * *. Moreover, hydroptropism as well as geotropism must be taken into 

account. * * *

I believe that the available evidence supports the conclusion 

that the false stem of Tempskya, or at least of T. knowltoni, 

may best be compared with the obliquely ascending and for the 

most part subterranean stem of such a fern as Dryopteris Mix 

mas.36

The new material which the writers have examined 

introduces some evidence that may help in the solution 

of the point at issue. Text figure 3 (p. 108) is a carefully 

prepared sketch of a cross section of an entire false 

stem of Tempskya grandis.

An interesting feature is the orientation of the true 

stems. Almost without exception they face directly 

toward the nearest point on the periphery of the mass— 

that is, there is a definitely organized radial arrangement in the false stem. The roots take a course parallel or very slightly divergent to that of the subparallel stems. Any deviations of great magnitude can 

be explained by the crowding and are purely local.

The most reasonable interpretation of this feature is, 

in the writers' opinion, that Tempskya grandis was an 

upright-growing plant, possibly with an axis of considerable length. It is difficult to harmonize any idea 

of a subterranean, oblique, or horizontal rootstock with 

the evidence. The height to which such a fascicle 

might rise with any degree of erectness is a matter for 

academic discussion. The mat of roots might prop 

the mass up to a considerable height, although such 

an arrangement is not so mechanically sound as a 

single stem of the same size. Probably the false stem 

tapered upward—that is, was conical—notwithstanding 

the evidence of Tempskya knowltoni Seward to the 

contrary. Though the base may have contained only a 

single stem it must be admitted that the mass of roots 

might be enlarged there and taper upward to the apex 

of the stems, where little other than the actual stems 

would be present. It is, of course, probable that 

most of the roots were produced only a short distance 

below the growing points. However, they probably 

elongated slowly, so that they could not attain such 

length as to increase noticeably the bulk of the false 

stem until they were some distance below the apex of 

the false stem. A significant feature pointing toward 

the formation of a swollen base and conical shape of 

the false stem is found in the fact that whereas roots 

are numerous root origins are relatively rare. This 

may be indicative of great length and profuse branching of the organs.

The condition in Tempskya knowltoni Seward is 

quite different. Text figure 2 (p. 108) illustrates the 

orientation of leaf bases in the false stem. Instead of 

a radial symmetry there is a very pronounced dorsi35 Seward, A. C., On a new species of Tempskya from Montana, Tempskya knowltoni 

sp. nov.: Annals of Botany, vol. 38, pp. 498-499, 1924.

ventral arrangement, which has led Seward 36 to the 

guarded assumption that the plant was horizontal or 

obliquely ascending and probably subterranean. Much 

can be said in favor of this assumption. The occurrence of coniferous roots in the false stem is cited as 

proof of the subterranean position of the mass. The 

exact category in which these so-called roots are to 

be placed, however, is in the writers' opinion uncertain. 

Possibly they are crushed portions of small stems. If 

T. knowltoni was obliquely ascending it is strange that 

the roots should so nearly parallel the stems, and it is 

begging the question to call in the influence of hydrotropism.

Several possibilities have been overlooked in previous 

discussions of the habit of Tempskya knowltoni Seward 

and similar dorsiventral types. The writers suggest 

that such forms may have been inclined or oblique in 

accordance with Seward's views but aerial and clambering over very steep hillsides, or they may have been 

climbers, either on cliffs or steep rock surfaces, or else 

lianalike and climbing on arborescent plants. Although 

there is no evidence at present of nearby land with 

any considerable relief, it must be borne in mind that 

material of Tempskya is well adapted to transportation and might have been brought in by currents 

from more distant rugged areas. These ideas are no 

more than suggestions made reasonable by the following facts:

The dorsiventrality of the false stem is as satisfactorily explained by the assumption of a climbing or 

clambering habit as by a subterranean one.

The roots might be expected to serve efficiently as 

holdfasts.

The false stem, if it is regarded as a mechanical unit, 

should be quite efficient in a cliff climber or liana, inasmuch as the demands for the utmost strength and at 

the same time extreme flexibility are fulfilled. The 

very sclerotic nature of the stems and roots is ample 

evidence of strength, and the aggregation of roots and 

stems into a ropy mass without cohesion of the elements 

would seem to permit flexibility.

The decay of the older portions of the stems may be 

cited as a possible adaptation toward the perching of a 

plant in crevices or possibly on some other plant or 

else on its own dead false stem. The loss of the older 

portions of the false stem through disintegration would 

relieve the strain on the plant and would permit its 

more efficient function as a liana or clamberer.

The situation in Tempskya minor is exactly comparable to that in T. knowltoni. The false stem shows 

a marked dorsiventrality, and in this species some of 

the masses are rather large, containing more than 50 

stems. It is most probable, in some species at least, 

that dorsiventrality was the condition during the 

entire life of the plant and did not change to a radial 

symmetry as maturity was approached.

3« Seward, A. C., op. cit., p. 605.
124 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

To summarize, there appears to have been considerable diversity of habit in the genus. Tempskya rossica 

Kidston and Gwynne -Vaughan and T. grandis certainly show a radial symmetry that may be linked with 

an upright habit. The exact height to which a false 

stem might rise is, of course, uncertain, but it could 

not have been very efficient. The basal portions were 

probably much enlarged by the concentration of roots, 

so that the mass tapered upward. Of course, there 

must have been a downward taper also in the extreme 

, basal region. In T. knowltoni Seward and T. minor 

dorsiventrality is very pronounced. The explanation 

may lie in the fact that the plant was subterranean 

and obliquely ascending. There is much evidence in 

favor of this assumption, but it is difficult to .explain 

the course of the roots parallel to the stems if this is 

true. The writers offer as an alternative the suggestion 

that the plant was a liana but do not urge it, because it 

may present some fundamental difficulties.

The false-stemmed or "tempskyoid" condition is by 

no means peculiar to Tempskya. Several examples are 

known, both living and fossil, and Sahni,37 in a recent 

paper, has summarized the facts concerning them.

The best-known living ferns that possess false stems 

are Todea barbara Moore and Hemitelia crenulata 

Mettenius. In Todea barbara the trunk is rather 

massive but low. The individual stems are radially 

constructed and arise both through repeated bifurcation and by lateral branching. In H. crenulata the 

stems are entirely the result of lateral branching of a 

central axis. These branches grow horizontally at 

first but turn upward on reaching the surface. The 

size attained is considerable.

In Salmi's paper there is described a very interesting 

zygopterid fern, Clepsydropsis australis Sahni, of Westphalian age, from localities in New South Wales. 

Sahni has clearly shown that this plant produced a false 

stem

of numerous repeatedly forked leaf-forming axes and relatively 

stout, erect petioles, the stems and petioles being all bound 

together by and embedded in a packing of adventitious roots and 

aphlebeae.38

The false stem shows a distinct radial organization 

both in the individual stems and the composite mass. 

It is likewise suggested that Clepsydropsis antigua and 

C. kingisica may have had false stems, although this 

has not yet been demonstrated.

These comparisons cannot be carried very far, for a 

number of reasons. In the first place, even though the 

systematic position of Tempskya is not definitely established, yet it is certainly quite distinct from any members of the Osmundaceae, Cyatheaceae, or Coenopteridaceae. The false stem of Tempskya is therefore 

the result of independent development and can be

« Sahni, Berbal, On Clepsydropsis australis, a zygopterid tree fern with a Tempskyalike false stem, from the Carboniferous rocks of Australia: Royal Soc. London Philos. 

Trans., ser. B, vol. 217, pp. 1-37 (especially pp. 27-29), pis. 1-6, 1928.

88 Idem, p. 19.

expected to differ in many significant respects from 

those developed in only distantly related families. 

Secondly, it is the only genus at present known to 

produce a false stem in which the individual axes are 

dorsiventral. Thirdly, it differs from other genera in 

that the aggregate is one of roots and stems with only 

a few petioles. In the other forms cited the petioles are 

notable constituents of the false stems.

STRATIGRAPHIC SIGNIFICANCE OF THE 

TEMPSKYACEAE

The recognition of specific differences among the 

specimens of American Tempskyas reported in this 

paper raises the question whether the species so differentiated are of any value in stratigraphic segregation. 

To answer this question the writers have tabulated 

stratigraphic sections from the localities where the 

specimens were collected or nearby areas and have 

attempted thus to show the relation between these 

sections and also, in a general way, to show the age 

relation of the American to the European occurrences. 

(See pi. 27.) This tabulation gives some sections in 

rather complete detail; others are somewhat meager 

because fuller information was not available. The 

fossil fern flora associated with the Tempskya species 

is given in a column to the right of that giving the 

stratigraphic names of the beds. The floral lists are 

confined to the ferns because the Tempskyas were 

ferns and because a list of the total flora for each locality 

would make such a table unwieldy and would probably 

serve no useful purpose in this connection. The lists 

therefore invite comparison and supply material for 

conjecture as to the probable reference of foliage to 

Tempskya. The following comments apply to the 

localities and the sections in which Tempskyas occur. 

The distribution of the Tempskyas within the United 

States is shown in figure 6.

Maryland.—The first American Tempskya to be 

described was Tempskya whitei Berry. The type specimen and others were collected in the valleys of Stony 

Run and Deep Run, north of Severn, Anne Arundel 

County, Md. The specimens were exposed by erosion 

of the Patapsco formation, which, in the Maryland 

Geological Survey's volume on the Lower Cretaceous,39 

is classed as the uppermost formation of the Potomac 

group (Lower Cretaceous). E. W. Berry, in discussing 

the age of the relatively large flora of the Patapsco 

formation, says:40

Moreover, the latter flora [Albian of Portugal] closely parallels 

the Patapsco, in that both mark the first abundant appeal ance 

of undoubted dicotyledons and a persistence of a considerable 

number of the earlier Cretaceous types, which survive in both 

the Patapsco flora and that of the Albian of Portugal.

On the basis of this close similarity between these two floras 

on opposite sides of the Atlantic, and the fact that both mark the 

first abundant appearance of Dicotyledonae, and the further

3 9 Clark, W. B., Bibbins, A. B., and Berry, E. W., The Lower Cretaceous deposits 

of Maryland: Maryland Geol. Survey, Lower Cretaceous, 1911. 

«Idem, p. 160.
125

fact that the Patapsco formation is overlain unconformably by 

the Raritan formation, carrying an abundant and unmistakably 

Cenomanian flora, the Patapsco formation is considered of 

Albian age. The unconformity which separates the Patapsco 

formation from the underlying Potomac beds is believed to 

represent all or nearly all of the time interval represented by the 

Aptian stage of European geology.

Montana.—Tempskya knowtioni Seward was the next 

Tempskya to be described. This specimen, according 

to the locality labels and as reported by Seward, was

collected in 1908 by A. C. Silberling in the Musselshell 

Valley at a point about 10 miles southeast of Harlowton, Mont. This information seemed rather indefinite 

to the writers, and accordingly after careful search 

they were fortunate in finding two letters by Silberling 

to F. H. Knowlton which gave the exact information 

required. The specimen was found in sec. 36, T. 7 JXT., 

R. 16 E., at a stratigraphic horizon "about 700 feet 

above the unconformity separating the Jurassic red

FIGURE 6.—Map showing Tempskya localities in the United States. 1, Head of 

Pack Creek, La Sal Mountains, Utah; 2, gravel terrace in T. 21 N., B. 117 W., 

Wyo.; 3,'sec. 36, T. 7 N., R. 16 E., Mont.; 4, sees. 17 and 18, T. 35 N., R. 115 W., 

Wyo.; 5, sec. 14, T. 31 N.. R. 115 W., Wyo.; 6, sec. 28, T. 41 N., R. 81 W., Wyo.;

7, sees. 17 and 19, T. 5 S., R. 44 E., Idaho; 8, hall a mile east of White Butte, 6 miles 

southwest of Kaolin, Clark County, Nev.; 9, mouth of Severn River, Anne Arundel County, Md.; 10, sec. 19, T. 5 N., R. 44 E., Idaho; 11, Lightning Creek, 1 

mile north of Greenhorn, sec. 9, T. 10 S., R. 35 E., Oregon.
126 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

beds from the Comanche and about 500 feet below the 

heavy Dakota sandstones." By superimposing this information on that acquired by later work the facts and 

terminology used by Silberling become clear. Plate 25 

of Bowen's bulletin 41 shows that the sec. 36 indicated 

by SilberUng lies on the structural feature called East 

dome of the Shawmut anticline and that all the rocks 

that crop out within the section are of Upper Cretaceous Colorado age. The "Jurassic red beds" mentioned by Silberling are the maroon beds of the Kootenai formation (Lower Cretaceous). The Comanche of 

Silberling is the undifferentiated Colorado shale, and 

the "heavy Dakota sandstones" are the Big Elk sandstone member of the Colorado shale. The area in 

which the Kootenai crops out in the section next to the 

west, in Middle dome, is both topographically and 

stratigraphically lower, thereby making it improbable 

that the Tempskya specimen could reasonably have 

come from the Kootenai formation by the usual natural 

means of transportation of geologic materials. The 

writers are convinced that the specimen was derived 

from the lower sediments of Colorado age and very 

likely from the undifferentiated zone below the Big 

Elk sandstone member. This zone probably represents 

the stratigraphic equivalent of the Mowry shale or 

Aspen shale and the Frontier formation of adjacent 

areas.

Wyoming and Teton Basin, Idaho.—The new Tempskyas more particularly described in this paper— 

Tempskya grandis and Tempskya minor—were collected 

by W. W. Eubey and J. S. Williams in the folded Cretaceous area north of Kemmerer, in west-central Wyoming, and by Eubey in the Teton Basin, Idaho. The 

horizon is in the porcelainlike beds of the Aspen shale, 

about 400 feet above the Bear Eiver formation; an 

excellent exposure is presented in the northeast corner 

of the Afton quadrangle, in sec. 17, T. 35 N., E. 115 W. 

The generalized section given below is supplied by 

Eubey, who writes:

The section is taken along part of the Green River-Snake 

River divide between Lookout Peak (southern end of the 

Hoback Range) and Deadman Mountain (northern end of the 

Wyoming Range). The beds that yield specimens of Tempskya 

are exposed at the head of Horse Creek.

Section of Cretaceous beds in -west-central Wyoming

Feet

Lower part of Frontier formation: Alternating soft 

dark-gray sandy shale and brown thin-bedded calcareous medium- to coarse-grained sandstone, with 

conglomeratic lenses, some thick beds of unconsolidated sand, and poor coal near the base. Basal portion contains [coniferous] petrified wood and fragmentary [coniferous and dicotyledonous] leaves. 

Marine invertebrates at several localities in upper 

part of unit__________^_____________..___.__._ 1, 000±

« Bowen, C. F., Anticlines in a part of the Musselshell Valley, Musselshell, 

Meagher, and Sweetgrass Counties, Mont.: U. S. Geol. Survey Bull. 691-F, pp. 

185-209, pi. 25, 1919.

Section of Cretaceous beds in west-central Wyoming—Continued

Feet 

Aspen shale (harder and lighter gray than overlying

and underlying units): 

Gray shale, thin beds of sandstone, and tuffaceous

shales.--..____._.________________——— 200±

Gray shale, thin beds of light-gray tuffaceous sandstone, dark-green siliceous shale, and silverygray dense cherty argillite. Specimens of 

Tempskya locally abundant__________________ 600±

Gray shale and thin beds of sandstone __________ 400 ±

Bear River formation (shale unit): Black and dark 

greenish-gray shale and mudstone with thin ferrugijfious layers in some places; contains the typical Bear 

River fauna.-____._-__-___------------------_-- 250±

Bear River formation (olive-brown quartzite unit, 

mapped as lower part of Bear River formation by A. R. 

Schultz): Very hard fine-grained olive-brown sandstone in 10- to 50-foot beds alternating with thicker 

beds of very dark gray shale_-____---_-_-----___- 150±

Alternation of dense gray limestone, shale, and purplish, 

pink, and gray calcareous shale. Mapped as upper 

part of Beckwith formation by A. R. Schultz. Corresponds to Peterson limestone, Bechler conglomerate, 

and Draney limestone of southeastern Idaho______ 400 ±

Westward these units thicken notably and undergo 

great lateral lithologic changes, making correlation 

difficult. The upper units are lost within a short 

distance, but the successively lower ones can be traced 

farther and farther westward. To judge merely by 

stratigraphic position and the general thickening, the 

Wayan formation of Idaho seems to occupy approximately the position of the upper part of the Bear 

Eiver, the Aspen, and possibly the lower part of the 

Frontier of adjacent areas in Wyoming. This correlation is further suggested by the similar lithologic 

character of portions of the Aspen and Wayan units, 

and especially by the more coarsely granular tuffaceous 

beds in the middle member of the Aspen, which resemble strikingly in both their field and microscopic 

characteristics the tuffaceous beds in the upper part of 

the Wayan.

The Aspen deposits that yield Tempskya are regarded 

as near-shore marine with some lagoonal and coastal 

swamp facies. In the Wyoming Eange and eastward 

and southeastward, particularly on the Meridian anticline southeast of Kemmerer, there are beds that carry 

marine fossils.42

One specimen of Tempskya grandis and one of 

Tempskya minor were collected by S. H. Knight, of 

the University of Wyoming, in sec. 14, T. 31 N., 

E. 115 W. As that section, according to A. E. 

Schultz's map,43 shows Bear Eiver deposits in the 

eastern half and Aspen deposits in the western half, 

and as neither is well exposed, Knight is uncertain as 

to the exact horizon from which the specimens were

12 Reeside, J. B., Jr., and Weymouth, A. A., Mollusks from the Aspen shale (Cretaceous) of southwestern Wyoming: U. S. Nat. Mus. Proc., vol. 78, art. 17, pp. 1-24, 

pis. 1-4, 1931.

« Schultz, A. R., Geology and geography of a portion of Lincoln County, Wyo.: 

U. S. Geol. Survey Bull. 543, pi. 1, 1914.
AMERICAN CRETACEOUS TERNS OF THE GENUS TEMPSKYA 127

collected but thinks that they probably came from 

beds near the top of the Bear River deposits. At any 

rate the material is not far from the lower limits of the 

Colorado group.

One small water-worn specimen of Tempskya minor 

was collected by R. W. Brown in June 1930 from a 

gravel terrace in the valley of the westward-flowing 

Twin Creek near the town of Fossil, in T. 21 N., 

R. 117 W., Wyo., the regional geology of which is 

described by Veatch.44 The debris of this gravel terrace 

includes, besides other rocks, some pebbles of igneous 

rock, no outcrop of which occurs within the present 

drainage basin of Twin Creek. The gravel has therefore not been derived entirely from the Tertiary 

bedrock on which it lies, but a portion must have 

come from some exterior source. The specimen of 

Tempskya, if the diagnosis of the stratigraphic significance of the species is correct, came from Upper 

Cretaceous deposits of Colorado age. The nearest 

area of outcrop of such deposits to the point where the 

specimen was found is across the low divide and in the 

townships next to the east, where Bear River, Aspen, 

and Frontier beds occur just east of Kemmerer. The 

inference that the specimen came from this area seems 

reasonable, but it involves the necessity of explaining 

some changes in drainage which the writers believe 

have taken place but the elucidation of which they 

deem not within their present undertaking.

A small collection of fossil plants made in the 

Powder River oil field, Wyo., by C. H. Wegemann in 

1910 has likewise yielded Tempskya minor. The 

specimen comes from a locality near the center of 

sec. 28, T. 41 N., R. 81 W., at the horizon of a coal 25 

feet below the base of the Mowry shale. Consequently it is from strata that are now called Thermopolis. Accordingly, the Thermopolis and the Mowry, 

which is conformable upon it, are considered to be 

correlated with the Aspen of western Wyoming—an 

idea that is well supported by other evidence.

Idaho, exclusive of the Teton Basin.—Several specimens of Tempskya minor were collected by G. R. 

Mansfield, W. W. Rubey, and J. S. Williams in the 

Lanes Creek quadrangle, southeast of Grays Lake 

and 40 miles west of the Horse Creek area, in Idaho. 

These specimens were found loose on the surface in 

sees. 17 and 19, T. 5 S., R. 44 E., in an extensive outcrop of the Wayan formation. Other specimens, 

according to Mansfield, were seen but not collected 

in the region northwest of Grays Lake. All these 

specimens were most probably derived from the uppermost beds of the Wayan formation, as these beds 

occupy the axial region of a broad syncline, and the 

course of the axis to the northwest in the region of 

Grays Lake Outlet marks the general line along which 

the specimens were found. The writers believe that

« Veatch, A. C., Geography and geology of a portion of southwestern Wyoming, 

with special reference to coal and oil: U. S. Geol. Survey Prof. Paper 56, pi. 3, 1907.

the finding of Tempskya minor in the Wayan formation only 40 miles distant from the Aspen localities in 

Wyoming, in a region of relatively similar lithology, 

indicates a fairly close correlation in age, and that the 

Wayan formation, or a portion of it, may reasonably 

be regarded as of Colorado age and the time equivalent 

of the Aspen shale of Wyoming. This conclusion was 

also independently reached by W. W. Rubey in his 

field studies of the stratigraphy and lithology of these 

beds.

Utah.—Frank L. Hess, of the United States Bureau 

of Mines, during an investigation of the carnotite 

deposits in the region of the La Sal Mountains, Utah, 

found a specimen of Tempskya lying in the soil on 

deposits overlying the Upper Jurassic Morrison formation (fMcElmo 45 of some reports). The locality 

is on the divide southwest of Winburn's ranch, near 

the head and on the northwest side of Pack Creek, 

just west of Mount Peale in the La Sal Mountains. 

As the specimen came from deposits above the Morrison, its source must lie between the Upper Cretaceous 

Dakota (?) sandstone and the Mancos shale. The 

Mancos shale is a dark marine shale deposit and is not 

likely to have contained the Tempskya. There remains 

the relatively thin deposit of light-colored Dakota (?) 

sandstone (about 40 feet), which, however, Hess did 

not distinguish as a separate unit in the section at 

the time of his visit. The outcrop of the Dakota (?) 

thickens and thins considerably in this area because 

its top was greatly eroded before the first deposits of 

the Mancos were laid down. It appears probable, 

therefore, that the Dakota (?) was the source of the 

Tempskya collected by Hess.

Nevada.—In 1934 fragments of Tempskya identified 

as T. minor were submitted to the writers by Eugene 

Callaghan and W. W. Rubey from the Overton fanglomerate, near Kaolin, Clark County, Nev. According to 

Rubey the fossils were obtained from the gray clays 

about 100 feet thick that constitute the basal member 

of the Overton. These beds have been reported as 

Tertiary.46 There is apparently no possibility that the 

material has been reworked from older deposits (Colorado Cretaceous). In consequence, at least the basal 

beds of the Overton, which are correlative with the 

Tempskya-be&ring beds, must be regarded as Colorado 

in age. Additional evidence in support of this opinion 

is found in the occurrence of a specimen of Microtaenia 

paucifolia (Hall) Knowlton, which is a fern indigenous 

to the Frontier and Aspen formations of Wyoming.

Oregon.—Two well-preserved specimens of Tempskya 

having the appearance of jasper were collected in 1914 

by J. T. Pardee from a placer pit on Lightning Creek

** A dagger (t) preceding a geologic name indicates that the name has been abandoned or rejected for use in classification in publications of the U. S. Geological 

Survey. Quotation marks, formerly used to indicate abandoned or rejected names, 

are now used only in the ordinary sense.

« Longwell, C. R., Geology of the Muddy Mountains, Nev.: U. S. Geol. Survey 

Bull. 798, pp. 68-74, 1928.
128 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1936

in the NE%NE% sec. 9, T. 10 S., R. 35 E., 1 mile north 

of Greenhorn, in the Sumpter quadrangle, Oregon. The 

age of the placer deposit has not been established but 

appears to be pre-Mascall. At any rate it is fairly 

certain that some of the material was derived from a 

Cretaceous source.

England.—Sussex, in southeast England, is crossed 

by a northwest-southeast anticlinal axis, which passes 

through Horsham and Tilgate Forest (St. Leonards) 

and emerges on the coast about 5 miles east of Hastings. 

This arch in the strata raises and exposes in the cliffs 

the Lower Cretaceous Wealden deposits known as the 

Hastings sands. This member of Wealden is commonly 

regarded as having three divisions, the lowest of which, 

the Ashdown sands, is, according to Evans,47 the source 

of specimens of Tempskya erosa. Dixon,48 however, 

gives a section in which he refers the T. erosa bands to 

either the upper part of the Ashdown sands or the lower 

part of the Wadhurst clays, but on page 144 he ascribes 

the T. erosa bands to the Wadhurst clays. The specimens weather out of the cliffs and accumulate on the 

beach near Ecclesbourne. Inland in Tilgate Forest 

presumably the same beds yielded the original specimens 

first reported by G. A. Mantell as "arborescent ferns" 

and later as Endogenites erosa. Tempskyas have also 

been collected from the Wealden of the Isle of Wight.

The occurrence of Tempskya erosa in the Lower 

Greensand (Aptian) at Potton, near Woburn, in Bedford, is discussed by Stopes 49 as follows:

Regarding the distribution of Tempskya u> the English Lower 

Greensand, so far as I can discover, the only specimens of the 

genus occur in the Potton sands. The beds at Potton are peculiar in containing a number of fossils which are certainly derived, 

it may be from the preceding Wealden deposits. These fossils 

generally show a richly colored, rolled, and often highly glazed 

surface, by which they can at once be distinguished by anyone 

well acquainted with the plants of the horizon. Of the specimens 

in the Museum, V. 13081 lacks the most noticeable characters 

of the derived fossils and might reasonably be regarded as a true 

Lower Greensand fossil. There is also one very fragmentary 

specimen from Ireland.

France.—Tempskya schimperi was collected by 

Carpentier ^ from two localities in the Wealden of 

northern France—one near Glageon, the other near 

Fourmies, about 3 kilometers distant. The Wealden 

deposits in this area overlie unconformably the calcareous Givetian and Frasnian beds of the Devonian and 

the Bathonian beds of the Jurassic. Overlying the 

Wealden are sands and clays that resemble the Lower 

Greensand and Gault, and, in spots like the Bois de 

Montfaux, immediately west of Glageon, the Qretaceous elements are capped by Eocene sands and clays. 

The Wealden of this region is confidently correlated by 

Carpentier with that of England on the basis of no less

« Evans, J. W., Geology of the British Isles, p. 248, 1918. 

« Dixon, Frederick, Geology of Susses, pp. 142, 144, 1878.

"Stopes, M. C., The Cretaceous flora, part 2, Lower Greensand (Aptian) plants 

of Britain; Catalogue of the Mesozoic plants in the British Museum (Natural History), p. 19, 1915.

50 Carpentier, Alfred, La flore wealdienne de Feron-Glageon (Nord): Soc. geol. 

• Nord Mem., vol. 10, p. 48, pi. 11, figs. 3-10, 1927.

than 22 species of fossil plants in common and with 

the Wealden of north Germany on the basis of 19 

species of fossil plants in common.

Germany.—Tempskya schimperi (originally Endogenites erosa) was reported by Wilhelm Dunker from 

the Hils beds (Hastings sands) at Neundorf, near 

Hannover. T. cretacea, a species regarded by Hosius 

and Von der Marck as different from T. schimperi, was 

collected in the Senonian near Haltern, in Westphalia.

Bohemia (Czechoslovakia).—From the Peruser beds 

of the Cenomanian of Rynholec, near Lana, 35 kilometers west of Prague, Joseph Velenovsky described 

Tempskya varians. The section showing the horizon 

where this species was collected is pictured by Fri6 and 

Bayer. 51 The Peruser beds of Bohemia have yielded 

127 species of fossil plants.

The specimens of the four Tempskyas—Tempskya 

pulchra, T. macrocaula, T. microrrhiza, and T. schimperi—described by A. J. Corda in 1845 were sent to 

him by three different persons and were thought by 

him to have come from the gravel along the Elbe River 

east of Neupaka, in Bohemia. It is particularly unfortunate that the exact source of the nominal type species, T. pulchra, of the now well-characterized genus 

Tempskya should be unknown.

Russia.—The specimen described by Kidston and 

Gwynne-Vaughan as Tempskya rossica was collected 

(according to the locality citation given by them) in 

the basin of the Karaganda River, on the west flank 

of the Mugodjar Mountains. The locality is about 15 

kilometers south-southeast of the Ber-Chogur station 

on the Tashkent Railway. That station is about 450 

kilometers east of Orenburg and about 75 kilometers 

west of Chelkar. The specimen apparently came from 

a Tertiary conglomerate that includes pebbles of 

crystalline rock and Devonian and Carboniferous limestone and sandstone. According to the more recent 

work of Prigorovsky 52 the Mugodjar Mountains, which 

are the southern extension of the Urals, heading toward 

the Ust-Urt Plateau between the Caspian and Aral 

Seas, are composed of igneous rocks—granite, diabase, 

gabbro, and porphyry—and of local disturbed or metamorphosed Devonian and Carboniferous sedimentary 

beds either covering the igneous rocks or being penetrated by them. On the west flank of the Mugodjars 

the upper drainage basin of the Emba River, of which 

the Karaganda is a tributary, is a region of Upper 

Cretaceous (Senonian) deposits that lie horizontally or 

almost horizontally but UD conformably upon the older 

Paleozoic beds. Prigorovsky's map (his pi. 35a) shows 

Tertiary deposits bordering those of the Upper Cretaceous in the Emba Valley, but t^his map, doubtless on

si Fric, Anton, and Bayer, Edvin, Studien im Gebiete der bohmischen Kreideformation; Palaeontologische Untersuchungen der einzelnen Scnichten; PeruSer Schichten: Archiv naturwiss. Landesd. Bohmen, p. 39, fig. 20, 1900.

. M Prigorovsky, M., Esquisse geologique des ibonts Mougodjars et des parties 

voisines des steppes de Tourgai et de l'Oural: C^m. geol. [St.-Petersbourg] Bull., 

vol. 33, pt. 2, pp. 889-928, pi. 35a, 1914.
AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA 129

account of its small scale and reconnaissance character, 

shows only Upper Cretaceous deposits at the locality 

where T. rossica is said to have been found. Tnat 

unmapped Tertiary terrace materials exist there secerns 

reasonable and that the T. rossica, specimen was derived 

from the surrounding Upper Cretaceous sediments and 

was deposited in the Tertiary gravel is the conclusion 

which, in the opinion of the writers, seems to fit this 

situation most satisfactorily.

Conclusions concerning stratigraphic range.—The r^nge 

of the genus Tempskya, as so far revealed, thus appears 

to have been from lowermost Lower Cretaceous time 

to Senonian time in the Upper Cretaceous. In America 

the record shows a range from the uppermost Lcjwer 

Cretaceous to a point well up in the earlier portion of the 

Upper Cretaceous. The fact that the European 

specimens, with the exception of T. rossica,, ar^ so 

poorly preserved makes identification and correlation 

difficult or even impossible on the basis of similarity 

or dissimilarity of species.

The American Upper Cretaceous Tempskyas^ as 

shown in the discussion of their anatomical structure, 

fall into two fairly well defined groups—the Tempskya 

grandis group and the Tempskya, knowltoni and .T. 

minor group. The Lower Cretaceous T. whitei appears 

to belong to the latter group, but its preservation, like 

that of the European specimens, is disappointing, and 

no definite statement can therefore be made in regard 

to its classification. The T. grandis group, to which 

also apparently belongs the Russian T. rossica, is 

regarded as anatomically more highly specialized than 

the T. knowltoni group. The T. knowltoni gifoup 

would therefore indicate a somewhat earlier development, which is compatible with the geologic record 

if T. whitei and the European Lower Cretaceous 

species can ever be proved to belong to the T. knowltoni 

group.

CONCLUSIONS

As a result of the investigation of a considerable 

quantity of material of Tempskya from various sources 

in western America the writers reach the following 

conclusions:

1. The genus Tempskya is characterized by a fijeely 

dichotomizing, dorsiventral, siphonostelic stem system 

sheathed in a thick and dense felt of diarch adventitious 

roots in such a manner that a false trunk is developed. 

The leaves are two-ranked on the upper surface of the 

stems and are marked by the emission of simplej inverted U-shaped triarch traces, which continue intc^ the 

base of the phyllopodium with but slight modification. The characters of the species are not sumikiarized here but are given in connection with the taxoncjmic 

details on pages 108-119.

2. The symmetry of the false trunk is either dprsiventral, as in Tempskya knowltoni, or radial, a& in 

T. grandis. This feature of false-trunk symmetry is 

suspected to be constant within the species.

3. The affinities of Tempskya are with the leptosporangiate ferns. There is evidence to indicate close 

proximity to the Schizaeaceae, but this is not conclusive. Certain features likewise indicate connections 

with the Loxsomaceae and the Gleicheniaceae. In 

view of this obscure relationship, a provisional family, 

the Tempskyaceae, is erected for the temporary inclusion of the genus.

4. The species that have been reported appear to 

fall into two natural subgeneric groups. The first is 

typified by Tempskya grandis and is characterized by 

large stems with short internodes, abundantly parenchymatous xylem, and a radial arrangement of the 

stems in the false trunk. The second group, the type 

example of which is T. knowltoni, is characterized by 

small stems with long internodes, a more homogeneous 

xylem, and a marked dorsiventrality of the false stem.

5. Of these two groups the one typified by Tempskya 

knowltoni is regarded as more primitive. The small 

stems with comparatively long internodes exhibit a 

more primitive solenostelic condition than those in 

the group of T. grandis, where, through a shortening of 

the internodal length, there is an approach toward 

polystely. The homogeneous xylem of T. knowltoni 

is taken to be less specialized than the parenchymatous 

xylem of T. grandis. The complex cortex of T. grandis 

is obviously an advanced character, although this is 

perhaps not a character of the whole subgeneric group. 

The radial symmetry of the false stem in T. grandis is 

regarded as probably derived from the dorsiventral 

stage represented by T. knowltoni.

6. As regards the habit, the stems of Tempskya 

grandis must have been upright. The radial symmetry 

of the false stem and the parallelism of the roots and 

stems is considered weighty evidence pointing in that 

direction. In the T. knowltoni group several possibilities are suggested. The symmetry of the false stem is 

dorsiventral, which may indicate a prone or obliquely 

ascending habit. The roots, however, run parallel to 

the stems, and this fact argues against such an explanation. As an alternative the suggestion is made that 

the plants may have been lianalike in habit or even 

epiphytic.

7. The few examples of false stems known in modern 

ferns are not comparable to the situation exhibited in 

Tempskya. Likewise the false-stemmed condition in 

other fossil ferns is somewhat different.

8. The occurrences of Tempskya, which have been 

reviewed, indicate that the stratigraphic range of the 

genus is from lowermost Lower Cretaceous to Senonian 

(late Upper Cretaceous). In western North America 

the genus is at present known definitely only from the 

lower part of the Colorado group, from the lower part 

of the Wayan formation, from the basal part of the 

Overton fanglomerate, and from beds that belong to 

either the top of the Bear River formation or the base 

of the overlying Colorado group.

PLATES 28-43

131

U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 28

X2

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1, 2. Transverse sections of Tempskya knowltoni showing general aspect of false stem.

3. Portion of slide shown in figure 2 enlarged to show relations of roots and stems in more detail.
U. S. GEOLOGICAL SURVEY

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Transverse section of Tempskya minor.

2. Transverse section of Tempskya grandis.

3. Portion of section of Tempskya knowltoni shown in plate 28, figure 1, enlarged to show more detail.
U. S. GEOLOGICAL SURVEY PLATE 30

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Transverse section of a stem of Tempskya knowltoni showing the characteristic solenos ;ele. Note the leaf traces, It' and If.

2. Transverse section of a decayed stem of Tempskya knowltoni. Note the penetrating roots, r.
IT. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 31

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Transverse section of a stem of Tempskya knowltoni showing an early stage in the emergence of a leaf trace (It).

2. Dichotomously branching stem of Tempskya knowltoni (leaf traces, II).
U. S. GEOLOGICAL SURVEY PEOFESSIONAL PAPEE 186 PLATE 32

4 5

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Transverse section of a portion of a false stem of Tempskya knowltcni showing two stems just above a dichotomy. 

3-5. Transverse sections of stems of Tempskya grandis showing general aspects. Note the dichotomy in figure 4.
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 33 

A "~"

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1-4. Transverse sections of stems of Tempskya grandis illustrating general characteristics. Note the sclerotic layers shown in the cortex and pith of the stem shown in 

figure 2. Likewise note the suggestion of short internodes indicated by the numerous leaf traces in any one section. In figure 4 two nearly free petioles are to 

be seen.
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 34

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Portion of a stem of Tempskya grandis showing an emerging leaf trace.

2. Transverse section of a stem of Tempskya grandis showing emerging leaf traces (It).

3. Portion of the stem xylem and adjacent tissues of Tempskya grandis. Note the occurrence of xylem parenchyma.

4. Transverse section of a portion of a stem of Tempskya grandis showing in particular the sclerotic tissue of the cortex.
TT. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER ]86 PLATE 35

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

., 2. Transverse sections of stems of Tempskya grandis illustrating emission of leaf traces. Note the petiole at Ib, figure 2.

i, 4. Higher magnification of stems shown in figures 1 and 2, showing successive stages in development of leaf traces (ff, It1, lt!, Iff).
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1-4. Transverse sections of Tempskya minor illustrating their general aspect. Note the dermal emergences (simple hairs) shown in figures 2 and 4.

p, Leaf base; r, root insertion.
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 37

X20

3 4

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1-4. Transverse sections of Tempskya minor illustrating general characteristics. Note the dichotomy of the stems and the occurrence of dermal hairs.
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 38

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Section of the stem of Tempskya minor showing the abundant epidermal hairs, apparently most numerous on the upper surface of the stem in the vicinity of the leaf 

bases.

2. Section of the stem of Tempskya minor showing the uninterrupted xylem cylinder at an internode.

3. Higher magnification of the stem shown in figure 1. Note the epidermal emergences or hairs at h.
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPEE 186 PLATE 39

3 4

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Longitudinal section of a stem of Tempskya minor cut near the apex, showing the investing epidermal hairs. 

3. Portion of the section shown in figure 1 taken at a higher magnification to show details of the hairs. 

3, 4. Transverse sections of stem of Tempskya minor showing the epidermal emergences.
U. S. GEOLOGICAL, SURVEY PROFESSIONAL PAPER 186 PLATE 40

X55

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Transverse sections of roots with attached root hairs in Tempskya minor. Note the lacunar zone in the outer cortex.

2. Longitudinal section of roots with attached root hairs.

3. 4. Transverse sections of roots showing details of structure and attachment of root hairs.

X55
tT. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 41

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Root of Tt-inpskya minor showing lacunar cortex.

2. Stern of Tempskya minor showing leaf traces, It 1. It*, It*.

3. Transverse section of the vascular cylinder of Tempskya minor showing details of structure. Note the suggestion of a long internode indicated by the absence of any 

leaf gap in the internodal area.

4. Transverse section of a root of Tempskya grandis showing details of morphology, px, Protoxylem; x, xylem; ph, phloem; en, endodermis; c, cortex.
IT. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 42

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1-3. Leaf bases of Tempskya grandis showing characteristic morphology, x, Xylem.

4. Leaf trace of Tempskya knowltoni showing details of morphology.

5. Leaf bases of Tempskya minor showing general features. Note the investing hairs.
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 186 PLATE 43

;X90

AMERICAN CRETACEOUS FERNS OF THE GENUS TEMPSKYA.

1. Longitudinal section of the stem of Tempskya grandis showing the scalariform tracheids.

2. Longitudinal section of the stem of Tempskya knowltoni cut through an emerging leaf trace and showing the scalariform tracheids. 

3-7. Longitudinal sections of roots of Tempskya knowltoni (fig. 3) and Tempskya grandis (figs. 4-7) showing xylem and adjacent tissues.

o