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Tinskya^ a New Genus of Seed-Bearing Callipterid Plants from the Permian of \ North-Central Texas

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Tinskya^ a New Genus of Seed-Bearing Callipterid Plants from the Permian of \ North-Central Texas Tinskya^ a New Genus of Seed-bearing Callipterid Plants From the Permian of \ North-Central Texas GEOLOGICAL SURVEY PROFESSIONAL PAPER 523-E Tinsleya, a New Genus of Seed-bearing Callipterid Plants From the Permian of North-Central Texas By SERGIUS H. MAMAY CONTRIBUTIONS TO PALEONTOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 523-E Tinsleya texana, the first known example of seed-bearing foliage in thefamily Callipterideae^ is described; biotic relationships and evolutionary implications are discussed UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1966 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 30 cents (paper cover) CONTENTS Page Description Continued Page Abstract ______________ El __________ E4 Introduction _ _ 1 6 2 8 Source of material 2 __________ 10 Age of material 2 ____---.__ 10 Previous studies _ ______________ 3 Biotic relationships of Tinsleya ___-____-. 11 Description. _____________ 3 Evolutionary significance _ __________ 13 General ___________ .. 3 References cited ________ 14 Foliar laminae ___________ 3 Index __________ 15 ILLUSTRATIONS [Plates follow index] PLATES 1-3. Compressions of Tinsleya texana. Page FIGURE 1. Venation of Tinsleya texana. E5 2. Seeds of Tinsleya texana., __ 7 CONTRIBUTIONS TO PALEONTOLOGY TINSLEYA, A NEW GENUS OF SEED-BEARING CALLIPTERID PLANTS FROM THE PERMIAN OF NORTH-CENTRAL TEXAS By SERGIUS H. MAMAY ABSTRACT appearance in rocks of earliest Permian age and, conse­ Tinsleya texana, n. gen. and sp., is described on the basis of quently, has been accepted as an important index fossil. a large suite of plant fossils from the upper part of the Lueders Callipteris and related taxa are generally regarded Limestone of the Wichita Group (Lower Permian) near Lake as members of the pteridosperm complex, but prior Kemp in Baylor County, Tex. In general aspect, Tinsleya is similar to the genus Callipteris to the present paper no factual evidence has been pre­ but differs in details of venation and polymorphism of the frond. sented to substantiate an ovuliferous reproductive Tinsleya is further unique in having seeds attached either api- habit. Indeed, the evidence bearing on the reproduc­ cally or marginally on a few pinnules. This occurrence is the tion of Callipteris has been limited until now to Remy's first known of seeds of any member of the Oallipterideae and (1953) description of Thuringia callipteroides from the establishes the group as truly pteridospermous. This type of fruiting habit may eventually lend important fossil support to Permian (Lower Rotliegende) coal-bearing strata the classical theory of derivation of the angiospermous carpel. near Crock, Thuringia, in Eastern Germany, and to Ro- selt's (1962) more recent discovery, also from the Lower INTRODUCTION Rotliegende of Thuringia, of organically connected Permian plant assemblages have been recorded from male fructifications to which he applied the name Cal- many geographic localities in both the Northern and lipterianthus amhardti. Thuringia was described as a Southern Hemispheres but principally from the south­ synangial fructification at least 28 mm long and about ern areas constituting Gondwana land. The southern 3.5 mm broad. It consists of several sporangia em­ floras are generally very limited in numbers of species bedded in a solid groundmass of sterile tissue and con­ and have commonly been regarded as depauperate as tains winged spores about 50/i in diameter. Preserva­ the result of having existed under postglacial condi­ tion of the material permitted investigation of epider­ tions. They are largely dominated by the ubiquitous mal features, and, on the basis of epidermal similarities genus G-lossopteris, whose problematical fructifications and association, Remy suggested that Thuringia is in have attracted considerable interest during the past 15 fact the male fructification of Callipteris conferta. Al­ years. (See Plumstead, 1952.) though Remy's interpretation seems reasonable, the or­ In contrast with the southern floras, the northern con­ ganic connection between fructification and foliage re­ temporary assemblages show considerably more taxo- mains to be demonstrated. nomic diversity and are generally in greater need of in­ Roselt's material, Callipterianthus, consists of a sin­ tensive investigation. Important among the northern gle frond fragment bearing both sterile and fertile Permian floras are the callipterids (Callipterideae of penultimate pinnules, so there is no doubt as to their Doubinger, 1956, p. 98), a highly variable and presum­ relationship. The sterile parts are of the deeply dis­ ably artificial complex of pteridophyllous plants that sected sphenopterid type, similar to Callipteris scheibei are stratigraphically restricted to rocks of late Paleo­ Gothan, C. owydata (Gb'ppert) Zeiller, or C. naumanni zoic age but which are broadly distributed geographi­ (Gutbier) Sterzel. As no epidermal comparisons were cally. The species Callipteris conferta (Sternberg) possible because of incomplete preservation, positive Brongniart has attracted more interest than any other identification was precluded, but Roselt speculated that single entity in this group, inasmuch as it makes its first Callipteriantlius was ascribable to Callipteris nau- El E2 CONTRIBUTIONS TO PALEONTOLOGY manni. The penultimate fertile pinnae are somewhat sequence consists of approximately 20 feet of siltstone longer than the sterile ones and have rather flexuose axes and sandstone, mostly thin bedded with variable fissil- ity, ranging in color from wThite to gray, bluish gray, bearingo undivided to twice-divided fertile "trusses." The fructifications consist usually of five, or in some six or tan and having considerable limonitic streaking. or seven, terminal groups of microsporangia, 2-2.5 mm The section is capped by a limestone bed that is light long, which apparently dehisced by slits along the inner gray in color, ranges from 2 to 3^2 feet in thickness, surfaces of the sporangial walls. The microspores are and contains minor amounts of sand. This bed is the round to oval, having dimensions of 20ju,-24ju, by 16ju.-18ju. only conspicuous limestone in the vicinity of the plant The present paper is based on a large assemblage of beds and doubtless is the unit mapped by Garrett, Lloyd, fragmentary foliar compressions and impressions of a and Laskey (1930) as the Mabelle Limestone of Romer CalUpt&ris-like plant having extremely variable foliar (1928). This fossiliferous site will be referred to here characteristics. Most of the fragments are sterile, but as the Lake Kemp locality (USGS paleobotany loc. a few specimens demonstrate the attachment of large 10,000). fertile-appearing structures that are interpreted here The exposure was originally created by a readout, and as evidence of the female reproductive organs. These the old roadbed itself is still evident at the bottom of plants occur with a few other taxa, principally walchian the bluff. Although finely comminuted plant debris is conifers. A brief announcement of the discovery of scattered sparsely through the entire sequence below this material was published in 1963 (U.S. Geol. Survey, the limestone unit, the best preserved plant material was 1963), while the study of Tinsleya was in a very pre­ found in a 1-foot unit of tan and bluish-gray siltstone, liminary stage. The most significant specimens were the base of which is about 5 feet above the old roadbed. found subsequently, during the fall field season of 1963. The beds in approximately the lower half of the section In view of its apparent dominance in this florule and its show minor angular unconformities and discordant significant bearing on the matter of reproductive habits bedding planes that suggest a channel-fill type of among the Callipterideae, however, this plant Tins­ deposition. Associated with and above the main plant- leya, new genus is regarded as of sufficient importance bearing strata are a number of thin bone beds that to warrant separate description at this time. contain fragmentary remains of a fresh-water fauna of small amphibians and paleoniscoid fishes. These beds ACKNOWLEDGMENTS and the presence of land-plant fossils indicate that the rock sequence at this locality represents a deltaic deposi- I was assisted in the field during the 1957, 1961, and tional environment in keeping with the generally 1963 seasons by Arthur D. Watt, U.S. Geological Sur­ accepted interpretations of the Permian rocks of this vey. Our thanks are due to Mr. Fred Parkey, general area. manager of Wichita County Water Improvement Dis­ AGE OF MATERIAL trict No. 2, who granted permission to collect on Lake Kemp grounds, where the material discussed in this The geology of Baylor County has not been mapped paper was found. recently, or in detail. The only county geologic map available (Garrett, Lloyd, and Laskey, 1930) is based SOURCE OF MATERIAL exclusively on surface exposures of a "few limestone The Tinsleya material was accumulated during four units, most of which are not named. The stratigraphic collecting trips in 1955, 1957, 1961, and 1963. It has position of the Lake Kemp strata relative to Romer's been found at only one locality thus far and represents Mabelle Limestone, however, places the plant beds at a at least 75 percent of the specimens obtained from this level slightly above the middle of the Lueders Forma­ particular site, where it occurs
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