Download or read book Middle Ordovician Crinoids from Southwestern Virginia and Eastern Tennessee written by James C. Brower and published by . This book was released on 1974 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the crinoid fauna of the Benbolt and allied formations of eastern Tennessee and southwestern Virginia. One new genus and 14 new species are proposed. These are Ectenocrinus punctalus, n. sp., anulocrinus latus, n. sp., Ristnacrinus ? altobasalis, n. sp., Hybocrinus punctatocristatus, n. sp., H. perperamnominatus, n. sp., Palaeocrinus planobasalis, n. sp., P. avondalensis, n. sp., Carabocrinus stellifer, n. sp., C. micropunctatus, n. sp., Pararchaeocrinus convexus, n., sp., Paradiabolocrinus irregularis, n. gen., n. sp., P. sinuorugosus, n. gen., n. sp., Rhaphanocrinus simplex, n. sp., and Wilsonicrinus culmensiuosus, n. sp. Due to poorly preserved material, two new species are not formally described but are referred to Isotomocrinus and Diabolocrinus. Two previously described species, Archaeocrinus peculiaris Miller and Gurley and Geraocrinus sculptus Ulrich, are treated here. The crinoid proposed by Miller and Gurley as Indianocrinus punctatus is a broken hybocrinid with some plates missing; consequently, Indianocrinus is placed in synonymy with Hybocrinus and the species retained as H. punctatus (Miller and Gurley). The pores of the Tennessee and Virgina palaeocrinids are shown to be respiratory; in addition, the ontogeny of the pores is discussed. Diabolocrinus vesperalis (White) is considered a highly variable form which includes six previously erected "species". As indicated in the above tabulation, the fauna is dominated by archaeocrinids, hybocrinids, and peculiar dicyclic cyathocrinid inadunates. The greatest faunal affinities are with the Chazyan crinoids of New York and adjacent areas and with the presumably specialized crinoids (e.g., Ristnacrinus, Hybocrinus, Carabocrinus, and Palaeocrinus) suggests that Late Chazyan and Black River time was an epoch of evolutionary experimentation for crinoids. Three of the peculiar genera survived the Black River, and persisted into the Trenton of North America, but they all became extinct prior to the Upper Ordovician. Most of the Benbolt and allied formation genera which failed to survive after the Black River epoch in North America are "normal" crinoids such as Anulocrinus, Pararchaeocrinus, Paradiabolocrinus, and Diabolocrinus. Reconstruction of the environment of the crinoids suggests that they were rooted in a relatively soft substrate and lived in shallow water of normal marine salinity and high oxygen content which was alternatingly agitated and calm. Agitated conditions probably prevailed as most species show structures which are best interpreted as adaptations to rough water conditions. The only crinoids which do not exhibit such adaptations are Geraocrinus sculptus Ulrich, two Palaeocrinus species, and Rhaphanocrinus simplex, n. sp.
Download or read book Calceocrinids from the Bromide Formation Middle Ordovician of Southern Oklahoma written by James C. Brower and published by . This book was released on 1977 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Echinoderm Faunas from the Bromide Formation middle Ordovician of Oklahoma written by James Sprinkle and published by . This book was released on 1982 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report Upon the Condition and Progress of the U S National Museum During the Year Ending June 30 written by United States National Museum and published by . This book was released on 1945 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pelmatozoan Columnals from the Ordovician of the British Isles written by S. K. Donovan and published by . This book was released on 1986 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report on the Progress and Condition of the U S National Museum for the Year Ending June 30 written by United States National Museum and published by . This book was released on 1920 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Southeastern Geology written by and published by . This book was released on 1977 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Middle Ordovician Echinoderns from Northern Illinois and Southern Wisconsin written by Dennis R. Kolata and published by . This book was released on 1976 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geobiology of Echinoderms written by Johnny A. Waters and published by . This book was released on 1997 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Advances in Geomathematics An International Symposium written by D.F. Merriam and published by Elsevier. This book was released on 2014-05-23 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent Advances in Geomathematics - An International Symposium
Download or read book Ordovician from the Andes written by and published by . This book was released on 2003 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contributions from the Museum of Geology written by University of Michigan. Museum of Paleontology and published by . This book was released on 1995 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Report written by United States National Museum and published by . This book was released on 1942 with total page 1118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletins of American Paleontology written by and published by . This book was released on 2002 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleozoic sequence stratigraphy views from the North American Craton written by Brian J. Witzke and published by Geological Society of America. This book was released on 1996-01-01 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Great Ordovician Biodiversification Event written by Barry D. Webby and published by Columbia University Press. This book was released on 2004-04-14 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two of the greatest evolutionary events in the history of life on Earth occurred during Early Paleozoic time. The first was the Cambrian explosion of skeletonized marine animals about 540 million years ago. The second was the "Great Ordovician Biodiversification Event," which is the focus of this book. During the 46-million-year Ordovician Period (489–443 m.y.), a bewildering array of adaptive radiations of "Paleozoic- and Modern-type" biotas appeared in marine habitats, the first animals (arthropods) walked on land, and the first non-vascular bryophyte-like plants (based on their cryptospore record) colonized terrestrial areas with damp environments. This book represents a compilation by a large team of Ordovician specialists from around the world, who have enthusiastically cooperated to produce this first globally orientated, internationally sponsored IGCP (International Geological Correlation Program) project on Ordovician biotas. The major part is an assembly of genus- and species-level diversity data for the many Ordovician fossil groups. The book also presents an evaluation of how each group diversified through Ordovician time, with assessments of patterns of change and rates of origination and extinction. As such, it will become the standard work and data source for biotic studies on the Ordovician Period.
Download or read book Northeastern Geology and Environmental Sciences written by and published by . This book was released on 1998 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
