Vertebrate Paleontology of the Southern High Plains Gerald E

New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/23 Vertebrate paleontology of the Southern High Plains Gerald E. Schultz, 1972, pp. 129-133 in: East-Central New Mexico, Kelley, V. C.; Trauger, F. D.; [eds.], New Mexico Geological Society 23rd Annual Fall Field Conference Guidebook, 236 p. This is one of many related papers that were included in the 1972 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico. 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One printed copy of any materials from the NMGS website or our print and electronic publications may be made for individual use without our permission. Teachers and students may make unlimited copies for educational use. Any other use of these materials requires explicit permission. This page is intentionally left blank to maintain order of facing pages. VERTEBRATE PALEONTOLOGY OF THE SOUTHERN HIGH PLAINS by GERALD E. SCHULTZ Department of Geology Anthropology West Texas State University, Canyon, Texas The southern High Plains of eastern New Mexico and the COLORADO Texas Panhandle cover an area of approximately 50,000 square miles. That portion lying south of the Canadian River forms a broad plateau called the Staked Plains or Llano Estacado which is bordered on the north, east, and west by escarpments and which grades southward into the Edwards OKLAHOMA Plateau without any physiographic break. North of the TEXAS —1 Canadian River, the plains are continuous with the High Plains of western Oklahoma, Kansas, and Nebraska. The present High Plains surface has developed on a widespread sheet of Late Tertiary and Quaternary deposits laid down on a low-relief surface of Permian, Triassic, and Cretaceous sedimentary rocks. In the southern High Plains, this surface is underlain by the thick caliche caprock which occurs in the upper part of the geographically extensive Ogallala Formation. Locally, basins and valleys eroded in the Ogallala Formation have been filled with lacustrine and fluvial deposits of Pleistocene age. Erosion and deposition during Pleistocene and Recent time have modified the surface features on the plains and have also developed or modified the canyons and escarpments along the margins of the plains thus exposing some of the older geological formations. Today, strata of Permian, Triassic, Pliocene, and Pleistocene ages may be seen and studied along the "breaks" of the Canadian River and along the head ward tributaries of the Red and Brazos Rivers. With the exception of the Permian, these beds contain abundant vertebrate fossils and, as a result, the southern High Plains, especially the Panhandle regions of Texas and Oklahoma, have long been known to vertebrate paleontologists throughout the world. During the past 80 years many institutions have made extensive collections of Triassic and Cenozoic vertebrates. Among these are the American Museum of Natural History and the Frick Laboratories of New 50 MILES York City, the University of California, the University of Michigan, Yale University, the University of Texas, the Figure 7. Index Map Showing Principal Vertebrate Fossil University of Oklahoma, West Texas State University, and Localities in the Southern High Plains. Midwestern University. Associated with these expeditions are the names of well-known paleontologists such as Cope, Gidley, Key to Faunal Sites Shown on Figure 1 (Map) Case, Matthew, Stirton, Lull, Stovall, and Savage. Figure 1 is a 1. LS (Ware) Ranch—Upper Triassic map of the southern High Plains and "panhandle" regions 2. Kenton Dinosaur Quarry—Upper Jurassic showing some of the major fossil vertebrate localities. A 3. Clarendon—Clarendonian (Early Pliocene) generalized geologic column showing the stratigraphic 4. Beaver—Clarendonian 5. Higgins—Early Hemphillian (Middle Pliocene) relationship of these vertebrate faunas is given in Table 1. 6. Hemphill (Coffee Ranch)—Mid-Hemphillian Beds of Upper Triassic age belonging to the Dockum Group 7. Goodnight—Mid-Hemphillian are exposed in the Tucumcari, New Mexico region and along 8. Optima—Mid-Hemphillian the breaks of the Canadian River from Logan, New Mexico to 9. Axtel—Late Hemphillian Cita Canyon—Blancan just north of Amarillo, Texas, and along the eastern escarp- Cudahy—Irvingtonian (Middle Pleist.) ment bordering the High Plains from about Amarillo south to 10. Christian Ranch—Late Hemphillian Big Spring, Texas. These gray sandstone and maroon and 11. Blanco—Blancan orange shale beds were laid down in streams and swamps and 12. Channing—Blancan have yielded numerous remains of phytosaurs and meto- 13. Red Corral—Blancan 14. Rock Creek—Irvingtonian posaurid amphibians as well as occasional teeth of lungfish. Cudahy—I rvingtonian One quarry site northeast of Amarillo was worked in 1940 15. Slaton—Rancholabrean (Late Pleist.) 129 Period or Epoch Stage—Age Vertebrate Faunas Rock Unit Pleistocene Rancholabrean Slaton Irvingtonian Cudahy Tule Fm. Rock Creek Blancan Blanco, Cita Canyon, and Blanco Fm. and Channing equivalents Red Corral Pliocene Hemphillian Axtel, Christian Ranch Ogallala Fm. Hemphill, Goodnight, Optima Higgins Clarendonian Clarendon, Beaver Cretaceous Lower Purgatoire Fm. Jurassic Upper Kenton Dinosaur Quarry Morrison Fm. (eastern New Mexico, Okla.) Triassic Upper LS (Ware) Ranch Dockum Grp. Permian Upper Quartermaster Fm. Cloud Chief Table 1. Composite Geologic Column for the Southern High Plains with WPA help and yielded over 20 skulls and other skeletal of Paleocene through Miocene age are known from the region. elements of the large metoposaurid amphibian commonly During the Pliocene, however, streams flowing eastward out of known as Buettneria. This collection, housed in the Pan- the Rocky Mountains deposited the silts, sands, and gravels of handle-Plains Historical Museum in Canyon, Texas, is one of the Ogallala Formation—easily recognized by its general buff the finest collections of these amphibians in North America. color and by its thick caprock of caliche which forms the High Throughout much of the Texas Panhandle, a hiatus exists in Plains surface. At times, environmental conditions favored the the stratigraphic section between the Upper Triassic and the burial and preservation of vertebrates in lakes, ponds, chan- late Tertiary. In eastern New Mexico and in the western Okla- nels, sinkholes, and on flood plains. Erosion has now exposed homa Panhandle, the Upper Jurassic is represented by con- these fossilifcrous units in many areas. The great abundance tinental deposits of the Morrison Formation and dinosaur and variety of Lower and Middle Pliocene horses, camels, bones have been found west of Boise City near Kenton, Okla- mastodons, rhinoceroses, deer, and carnivores which have been homa. Near-shore marine rocks of Lower Cretaceous age occur found in certain parts of the Texas Panhandle prompted Wood from the vicinity of Tucumcari, New Mexico southeastward and others (1941) to designate these areas and their faunas as toward Lubbock, Texas, but are generally absent northeast of the basis for the Clarendonian (Lower Pliocene) and this line except for a few small outliers. In addition to Hemphillian (Middle Pliocene) mammalian ages of North numerous invertebrates, the Cretaceous rocks have yielded America. These, along with the other mammalian ages of the occasional shark teeth. Tertiary, are generally defined on the basis of the first and last The early and middle Tertiary was apparently a time of appearances and joint associations of certain characteristic erosion or nondeposition in the southern High Plains. No rocks mammalian genera. 130 The term Clarendonian is derived from the town of Claren- include large bearlike forms (lschyrocyon), large heavy-jawed don in Donley County, Texas. North of Clarendon, the Salt bone-eaters (Aelurodon), and terrier-sized forms like Fork of the Red River flows through Permian rocks. Along the Tomarctus. Mustelids and saber-toothed cats are among the divides north of the river are exposures of Pliocene strata rarer carnivores. Teleoceras is a rather common, short-legged, where fossils

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