STATE OF ILLINOIS ADLAI E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION NOBLE J. PUFFER, Director DIVISION OF THE STATE GEOLOGICAL SURVEY M. M. LEIGHTON, Chief URBANA REPORT OF INVESTIGATIONS—NO. 142 PTERIDOSPERM MALE FRUCTIFICATIONS : AMERICAN SPECIES OF DOLEROTHECA, WITH NOTES REGARDING CERTAIN ALLIED FORMS BY JAMES M. SCHOPF Reprinted from the Journal of Paleontology Vol. 22, No. 6, November, 1948 PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS URBANA, IIXINOIS 1949 ORGANIZATION STATE OF ILLINOIS HON. ADLAI E. STEVENSON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION HON. NOBLE J. PUFFER, Director BOARD OF NATURAL RESOURCES AND CONSERVATIO: HON. NOBLE J. PUFFER, Chairman W. H. NEWHOUSE, Ph.D., Geology ROGER ADAMS, Ph.D., D.Sc, Chemistry LOUIS R. HOWSON, C.E., Engineering A. E. EMERSON, Ph.D., Btology LEWIS H. TIFFANY, Ph.D., Forestry GEORGE D. STODDARD, Ph.D., Litt.D., LL.D., L.H.D. President of the University of Illinois GEOLOGICAL SURVEY DIVISION M. M. LEIGHTON, Ph.D., Chief _ SCIENTIFIC AND TECHNICAL STAFF OF THE STATE GEOLOGICAL SURVEY DIVISION 100 Natural Resources Building, Urhana M. M. LEIGHTON, Ph.D., Chief ENID TOWNLEY, M.S., Assistant to the Chief Velda a. MiLLAKD, Junior Asst. to the Chief Elizabeth Stephens, B.S., Geological Assistant Helen E McMoRRis, Secretary to the Chief Elizabeth Wray, A. A., Technical Assistant Berenice Reed, Supervisory Technical Assistant Norma J. Parge, A.B., Technical Assistant GEOLOGICAL RESOURCES GEOCHEMISTRY Frank H. Reed, Ph.D., Chief Chemist (on leave) D.Sc, Principal Geologist Arthur Bevan, Ph.D., Grace C. Johnson, B.S. Research Assistant Coal Coal G H Cady, Ph.D., Senior Geologist and Head G. R. YoHE, Ph.D., Chemist and Head " Mechanical Engineer r" J Helfinstine, M.S., Ruth C. Wildman, M.S., Assistant Chemist Robert M. Kosanke, M.A., Associate Geologist Wm. F. Loranger, B.A., Research Assistant John A. Harrison, M.S., Assistant Geologist Tack A. Simon, M.S., Assistant Geologist^ (on leave) Industrial Minerals Raymond Siever, M.S., Assistant Geologist S. Machin, Ph.D., Chemist and Head Barnes, M.S., Assistant Geologist J. Mary E. Tin Boo Yee, M.S., Assistant Chemist Parker, B.S., Assistant Geologist Margaret Paulene Ekman, B.A., Research Assistant Kenneth Clegg, Technical Assistant Fluorspar Oil and Gas G. C. Finger, Ph.D., Chemist and Head Geologist and Head H. Bell, Ph.D., _ HoRST Schneider, B.S., Special Assistant Chemist A Engineer G. Frederick Squires, A.B., B.S., Petroleum William Frederick Buth, B.S., Special Research David H. Sv^^ann, Ph.D., Geologist Assistant Virginia Kline, Ph.D., Associate Geologist Richard Blough, B.A., Research Assistant Wayne F. Meents, Assistant Geologist Robert E. Oesterling, B.A., Special Research Assistant Petroleum En- Richard J. Cassin, B.S., Assistant gineer L. Finnerty, Special Research Assistant , A ^ J. James B.S., Lester W. Clutter, B.S., Research Assistant Nancy Cassin, B.S., Research Assistant Chemical Engineering H. W. Jackman, M.S.E Chemical Engineer and Industrial Minerals Head P. W. Henline, M.S., Chemical Engineer E. Lamar, B.S., Geologist and Head J. B. Greenwood, B.S., Mechanical Engineer Robert M. Grogan, Ph.D., Geologist J. James C. McCullough, Research Associate Raymond S. Shrode, B.S., Assistant Geologist X-ray and Spectrography Clay Resources and Clay Mineral Technology W, F. Bradley, Ph.D., Chemist and Head Ralph E. Grim, Ph.D., Petrographer and Head William A. White, M.S., Associate Geologist Physics Herbert D. Glass, M.A., Associate Geologist Kenneth B. Thomson, Ph.D., Physicist Groundwater Geology and Geophysical R. J. PiERSOL, Ph.D., Physicist Emeritus Exploration Analytical Chemistry Carl A. Bays, Ph.D., Geologist and Engineer, and *0. W. Rees, Ph.D., Chemist and Head Head . L. D. McVicker, B.S., Chemist ^ , Robert R. Storm, A.B., Associate Geologist Howard S. Clark, A.B., Associate Chemist Merlyn B. Buhle, M.S., Associate Geologist Emile D. Pierron, M.S., Assistant Chemist M. W. PuLLEN, Jr., M.S., Associate Geologist Elizabeth Bartz, A.B., Research Assistant John W. Foster, B.A., Assistant Geologist Donald Russell Hill, B.S., Research Assistant Richard F. Fisher, M.S., Assistant Geologist Ruth E. Koski, B.S., Research Assistant Draftsman Margaret J. Castle, Assistant Geologic Annabelle G. Elliott, B.S., Technical Assistant Geologist Robert Knodle, M.S., Assistant MINERAL ECONOMICS Engineering Geology and Topographic Mapping W. H. Voskuil, Ph.D., Mineral Economist George E. Ekblaw, Ph.D., Geologist and Head W. L. BuscH, Research Associate Nina Hamrick, A.M., Assistant Mineral Economist Ethel King, Research Assistant Areal Geology and Paleontology M. H. B. WiLLMAN, Ph.D., Geologist and Head EDUCATIONAL EXTENSION Lovi^enstam, Ph.D., Geologist (on leave) Heinz A. Gilbert O. Raasch, Ph.D., Associate Geologist Ph.D., Geologist J. S. Templeton, in Charge Dorothy Ranney, B.S., Technical Assistant Geology Subsurface LIBRARY L. E. Workman, M.S., Geologist and Head Elwood Atherton, Ph.D., Associate Geologist Anne E. Kovanda, B.S., B.L.S., Librarian Paul Herbert, Jr., B.S., Associate Geologist Ruby D. Prison, Technical Assistant Donald Saxby, M.S., Assistant Geologist Robert C. McDonald, B.S., Research Assistant PUBLICATIONS Lois Titus, B.S., Research Assistant Dorothy E. Rose, B.S., Technical Editor M. Elizabeth Staaks, B.S., Assistant Editor Mineral Resource Records Meredith M. Calkins, Geologic Draftsman Ardis Assistant Geologic Draftsman Vivian Gordon, Head D. Pye, Wayne W. Nofftz, Technical Assistant Harriet C. Daniels, B.A., Technical Assistant Leslie D. Vaughan, Associate Photographer Dorothy Gore, B.S., Technical Assistant Beulah M. Unfer, Technical Assistant Dorothy A. Foutch, Technical Assistant Zora M. Kaminsky, B.E., Technical Assistant •' Acting Chief Chemist in interim of absence of Elene Roberts, Technical Assistant Chief Chemist. Consultants: Geology, George W. White, Ph.D., University of Illinois Ceramics, Ralph K. Hursh, B.S., university of Illinois Mechanical Engineering, Seichi Konzo, M.S., University of Illinois Topographic Mapping in Cooperation with the United States Geological Survey. January 10, 1949 Digitized by tlie Internet Arciiive in 2012 witii funding from University of Illinois Urbana-Champaign http://archive.org/details/pteridospermmale142scho a Journal of Paleontology, vol. 22, no. 6, pp. 681-724, pls. 104-115, 18 text figs., November 1948 PTERIDOSPERM MALE FRUCTIFICATIONS: AMERICAN SPECIES OF DOLEROTHECAy WITH NOTES REGARDING CERTAIN ALLIED FORMS JAMES M. SCHOPF U. S. Geological Survey, Washington, D. C. Abstract—Dolerotheca includes a group of pteridosperms (MeduUosaceae) char- acterized by very large and unusual pollen-bearing organs. Their botanical p)er- tinence to plant microfossil studies and to phyletic theories, as well as their rarity in good preservation, lends considerable interest to these fossils. The rnorphology of the polleniferous organs, or male fructifications, is reviewed preliminary to taxonomic treatment of the new American material. Three new species are described in considerable detail both as to general external form and internal organization— result possible only because of preservation in the limestone concretions in coal beds known as coal balls. The species of Dolerotheca are assembled in a new sub-tribe called the Dolerothecinae. The evidence for relating these forms with other coal- bail fossils known as Myeloxylon, and, in turn, with MeduUosa, is discussed with par- ticular reference to one species where the peduncular organ of attachment seems to be preserved. Notes are also included regarding a specimen of Dolerotheca pre- served in surface imprint in an ironstone concretion, and regarding the allied Whit- tleseyinean group classed as Codonotheca. The relationships and comparative anatomy of Dolerotheca with other pteridosperm groups that present homologous features are discussed and a tentative evolutionary interpretation presented. Hetero- theca of the Lower Carboniferous appears to represent a plausible ancestral type, combining features of both the lyginopterid and meduUosan lines of descent. The morphology of Dolerotheca suggests, however, that evolutionary modification has been by elaboration and septation of a single telomic structure rather than by adna- tion and concrescence of many. INTRODUCTION that dififer radically from organs known in THE male fructifications of pteridosperms ferns. A more complete understanding of the are less well understood than most of characteristics and the nature of the diver- the other organs pertaining to this large sity of male fructifications in pteridosperms group of ancient plants. The fact that a will have important influence on ideas of considerable number of the Paleozoic fern- phylogeny and relationship among this like plants bore seeds and hence were not large, chiefly Paleozoic, plant alliance. true ferns, in spite of their highly dissected Among the pteridosperms the plants or pinnatifid leaves, became established classified as Dolerotheca display conspicuous about 45 years ago. Since then a number of differences with regard to their male fruc- pteridosperm seed types have become well tifications. Such fructifications of Dolerotheca known; on the other hand an equivalent have not been commonly reported, and up amount of information has not been ob- to the time specimens here described were tained about the male fructifications de- discovered, only a single fragment was spite the fact they must have been numer- known which showed well preserved tissue ous. Some of the first recognized