Download or read book Ontogenetic and Stratigraphic Cranial Variation in the Ceratopsid Dinosaur Triceratops from the Hell Creek Formation Montana written by John Benedetto Scannella and published by . This book was released on 2015 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypotheses regarding the taxonomy and systematics of non-avian dinosaurs are based on analyses of morphology. As such, it is critical to assess the potential roles of intraspecific variation in systematic interpretations. Ontogenetic (developmental) change has been found to be a potential contributor to taxonomic confusion in the fossil record of dinosaurs. Similarly, variation between specimens found at different stratigraphic levels should be assessed in order to decipher variation within and between closely related taxa. The chasmosaurine ceratopsid Triceratops has had a complicated taxonomic history due to variation in cranial morphology between specimens. Recent work in the uppermost Cretaceous Hell Creek Formation (HCF) has produced a large (n>50) new sample of specimens. Using this data set its possible to reassess variation in Triceratops and further explore chasmosaurine paleobiology. Building on previous work on Triceratops ontogeny, examination of the parietal-squamosal frill finds that these bones underwent a dramatic transformation late in ontogeny. The short, solid frill of Triceratops expanded into a more elongate, thin, fenestrated condition, which had previously been found to characterize the coeval ceratopsid taxon Torosaurus latus. This suggests that these taxa are synonymous with Torosaurus representing the mature form of Triceratops rather than a distinct taxon. Further, Nedoceratops hatcheri, which is represented by a single specimen with a small fenestra in the parietal, is hypothesized to represent a transitional morphology between unfenestrated and fully fenestrated (Torosaurus) specimens. Detailed locality information for specimens collected over the course of the Hell Creek Project permits for the placement of specimens in stratigraphic context. The two currently recognized species, T. horridus and T. prorsus, are stratigraphically separated within the HCF and cladistic and stratocladistic analyses are consistent with the evolution of Triceratops incorporating anagenetic (transformational) change. Morphometric analyses of the extant archosaur Ceratogymna atrata (the Black-casqued hornbill) indicate that enlarged cranial structures function as objects of visual display. Morphometric studies of Triceratops further suggest that specimens found lower in the formation may have attained the Torosaurus frill morphology through ontogeny, whereas this basal condition became increasingly rare higher in the formation. Morphometric results are also consistent with early divergence between two distinct genera.
Download or read book The Hell Creek Beds of the Upper Cretaceous of Montana written by Barnum Brown and published by . This book was released on 1907 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Brachyceratops written by Charles Whitney Gilmore and published by . This book was released on 1917 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Hell Creek Formation and the Cretaceous Tertiary Boundary in the Northern Great Plains written by Joseph Herbert Hartman and published by Geological Society of America. This book was released on 2002 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Age and Stratigraphic Relations of the Ceratops Beds of Wyoming and Montana written by Timothy William Stanton and published by . This book was released on 1909 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Bug Creek Problem and the Cretaceous Tertiary Transition at McGuire Creek Montana written by Donald L. Lofgren and published by Univ of California Press. This book was released on 1995-08-31 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bug Creek assemblages from Montana, transitional in composition between typical Cretaceous and Paleocene vertebrate faunas, are critical to K-T extinction debates because they have been used to support both gradual and catastrophic K-T extinction scenarios. Geological and palynological data from McGuire Creek indicate that Bug Creek assemblages are Paleocene and restricted to channel fills entrenched into older sediments, suggesting that the Cretaceous component of the assemblage was reworked. Thus, the author concludes, "Paleocene dinosaurs" are an illusion and the K-T survival rate of mammals is low because the presence of Cretaceous mammals in Bug Creek assemblages is also the result of reworking.
Download or read book New Perspectives on Horned Dinosaurs written by Michael J. Ryan and published by Indiana University Press. This book was released on 2010 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: Easily distinguished by the horns and frills on their skulls, ceratopsians were one of the most successful of all dinosaurs. This volume presents a broad range of cutting-edge research on the functional biology, behavior, systematics, paleoecology, and paleogeography of the horned dinosaurs, and includes descriptions of newly identified species.
Download or read book Brachyceratops A Ceratopsian Dinosaur from the Two Medicine Formation of Montana with Notes on Associated Fossil Reptiles written by Charles Whitney Gilmore and published by . This book was released on 2017-08-21 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Brachyceratops written by Charles Whitney Gilmore and published by Nabu Press. This book was released on 2014-03 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a reproduction of a book published before 1923. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant marks, etc. that were either part of the original artifact, or were introduced by the scanning process. We believe this work is culturally important, and despite the imperfections, have elected to bring it back into print as part of our continuing commitment to the preservation of printed works worldwide. We appreciate your understanding of the imperfections in the preservation process, and hope you enjoy this valuable book.
Download or read book New Notes on the Osteology of Triceratops written by Barnum Brown and published by . This book was released on 1906 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fossil Record 6 Volume 1 written by Spencer G. Lucas and published by New Mexico Museum of Natural History and Science. This book was released on with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ceratopsia written by John Bell Hatcher and published by . This book was released on 1907 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Indian Mesozoic Chronicle written by Jai Krishna and published by Springer. This book was released on 2017-03-11 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book reviews and summarizes the Indian Mesozoic geological evolution in an innovative alternative perspective of sequence stratigraphy. It mainly focuses on the Jurassic interval, but also concisely discusses the preceding Triassic and Cretaceous geological records. The key to the study is primarily held in the recently developed ammonoid based high resolution scales in the Triassic and Jurassic period. The Indian Jurassic record is thus elevated to a high resolution pedestal. The large intra-Jurassic stratigraphic gap in Kachchh, with increase in duration from margin to basin, has been précised in different sections, along with radical revision of its long held interpretation from sub-aerial to sub-marine all over from Arabia to Australia. Other significant gaps are also differentiated into sub-aerial and sub-marine. The Indian Late Precambrian – Neogene record is organized into five mega-sequences. Among these, the fourth – also the most important one – includes the intra-Permian to Early Eocene interval from the origin to the closure of the Neotethys. Based on multidisciplinary integration of the Indian Mesozoic geological record and comparison with hydrocarbon producing basins on east and west of India, a highly positive scenario of the hydrocarbon source/reservoir sediment perspective is outlined in the book in sequence stratigraphic backdrop as an edifice for future elaborate evaluation.
Download or read book The Hell Creek Beds Of The Upper Cretaceous Of Montana written by Barnum Brown and published by . This book was released on 2023-07-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Brachyceratops written by Charles Whitney Gilmore and published by . This book was released on 2015-02-12 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Download or read book Through the End of the Cretaceous in the Type Locality of the Hell Creek Formation in Montana and Adjacent Areas written by Gregory P. Wilson and published by Geological Society of America. This book was released on 2014-01-21 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The chapters represent a surge of field and laboratory research activity, illustrating the impacts of new and refined methods and tools. This volume explores geologic and biologic history preserved in the strata bounding the Cretaceous-Paleogene boundary"--Provided by publisher.
Download or read book Contributions to Late Cretaceous Stratigraphy and Paleontology Western Montana written by T. S. Dyman and published by . This book was released on 1991 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
