Biometrical Study of Morphology and Development of the Pennsylvanian Trilobite \u3ci\u3eAmeura sangamonensis\u3c/i\u3e (Meek and Worthen)

Biometrical study of morphology and development in a sample of 100 cranidia, 94 pygidia, 26 free cheeks, and 9 complete specimens of the trilobite Ameura sangamonensis (Meek and Worthen) from the Bonner Springs Shale (Pennsylvanian; Missouri Series) in eastern Nebraska indicates that the dominant growth pattern was isometric. Evidence supporting this conclusion consists of rectilinear size relations among eight pairs of cranidial dimensions, three pairs of pygidial dimensions, and three pairs of dimensions of the free cheeks. Qualitative changes in pygidial morphology during development include a progressive decrease in prominence of the border, increasing width of the posterior border relative to the lateral borders, and a progressive change in outline from a smoothly rounded semi-circular margin to one that is subtriangular or subparabolic. All the complete specimens in the sample are holaspides. There is some indication of point clustering on scatter diagrams among the smallest cranidia which suggests that the sample may contain a few late meraspides. However, if meraspid cranidia and free cheeks are present, they are morphologically very similar to the small holaspides

Fossil crinoid studies

54 p., 30 fig.http://paleo.ku.edu/contributions.htm

Some Late Pennsylvanian (Virgilian) Crinoids from Southeastern Nebraska and Southwestern Iowa

Virgilian age rocks of lowa and Nebraska contain important crinoid faunas and current collections help to establish distributions and tentative ranges of numerous species. A middle limestone-core shale fauna from the Cass Formation of Nebraska provides small, usually inornate species with close Missourian affinities. Other crinoids studied are from outside shales and upper limestones of the cyclothem and these are usually large, ornate species. Biserial arms are reported for the first time for Sublobalocrinus Knapp. The first report of flexible crinoids from Virgilian strata of the Iowa-Nebraska area is made here. Current collections of crinoids contain 40 species and 31 genera representing 19 families: new species or subspecies are; Isoallagecrinus bassleri intermedius, Graffhamierinus gratesquus, Arrectocrinus iowensis, Pyndoxocrinus inornatus, Sublobacrinus kaseri, Contocrinus invaginatus, Apographiocrinus platybasis. The species Aesiocrinus luxuris is referred to the genus Moundocrinus

Late Pennsylvanian and Early Permian Cyclic Sedimentation, Paleogeography, Paleoecology, and Biostratigraphy in Kansas and Nebraska

Overview of Upper Pennsylvanian Cyclic Sedimentation in Kansas and Nebraska Philip H. Heckel Department o( Geology University o( Iowa Contributions from: Christopher G. Maples, W. Lynn Watney Kansas Geological Survey, Lawrence, Kansas John Harris Shell Western Exploration and Production, Inc., Houston, Texas David Ball . Champlin Petroleum Co., Houston, Texas Philip H. Heckel University of Iowa, Iowa City, Iowa R. R. West, V. Voegeli, S. Roth, K. Leonard, H. R. Feldman, C. Cunningham Kansas State University, Manhattan, Kansas Royal H. Mapes Ohio University, Athens, Ohio Hans-Peter Schultze University of Kansas, Lawrence, Kansas R. M. Joeckel Florida Museum of Natural History Gainesville, Florida Peter Holterhoff University of Cincinnati, Cincinnati, Ohio Theodore Huscher University of Nebraska-Lincol

Southeast Nebraska Geology: Field Trip 3

The purpose of this trip is to familiarize you with the latest Pennsylvanian and earliest Permian rocks that are exposed in extreme southeastern Nebraska. You will see eight exposures of these rocks and will have ample opportunity to collect lithologic samples, as well as samples for both macro- and micro-fossils. The stops have been selected to show you examples of several different environments that existed in southeastern Nebraska in the late Paleozoic. These include subaerial deposits with paleosols, nearshore and offshore marine clastic and carbonate sequences. Each stop is covered in detail in the handouts that have been furnished to the trip participants. Subsequent readers will be able to find this information in the several references that are listed at the end of the text. All of the stops will be in Richardson and Pawnee counties (fig. 1)

Geologic History of Ash Hollow State Historical Park, Nebraska

Contents: Introduction Acknowledgments Cautions General Stratigraphy Oligocene Series-White River Group-Brule Formation-Whitney Member Miocene Series-Ogallala Group-Ash Hollow Formation Pliocene Series-Broadwater Formation Quaternary deposits Older colluvium and loess Younger colluvium and alluvium. General Paleontology Evidence of past life: fossils and subfossils Collecting fossils Vertebrate fossils Fossils from the Whitney Member of the Brule Formation. Plants Invertebrates Vertebrates Fossils from the Ash Hollow Formation Plants Invertebrates Vertebrates Fossils from the Broadwater Formation PlantsVertebrates Quaternary fossils Plants Invertebrates Vertebrates Additional studies of Nebraska fossils Geologic History Prehistory and History References Appendix I Appendix II Appendix III Appendix I

New Species of Arrectocrinus Knapp from Southwestern Iowa and Southeastern Nebraska

New species of Arrectocrinus Knapp from southwestern Iowa and southeastern Nebraska. Partial crowns of Arrectocrinus hopperi n.sp. show that the formerly poorly known arms of this genus are biserial and probably did not expand distalward. The Arrectocrinus range zones lowered to include the Beil Limestone Member of the Lecompton Formation (Virgilian). Possible affinities of Arrectocrinus with Erisocrinus are examined