Download or read book Ontogeny Intraspecific Variation and Systematics of the Late Cambrian Trilobite Dikelocephalus written by Nigel C. Hughes and published by . This book was released on 1994 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biometric analyses of well-localized specimens of the trilobite Dikelocephalus from the St. Lawrence Formation (Upper Cambrian), northern Mississippi Valley, suggest that all specimens belong to a single, highly variable morphospecies, D. minnesotensis. A complex pattern of ontogenetically-related and ontogeny-independent variation produced a mosaic of morphotypes, which show greater diversity than previously recorded within trilobite species. There is considerable variation within collections made from single beds. Variations of characters among collections are mosaic, and are clinal in some cases. Patterns of variation within Dikelocephalus cannot be related to lithofacies occurrence. There are no obvious temporal variations in D. minnesotensis within the St. Lawrence Formation, but some Dikelocephalus from the underlying Tunnel City Group may belong to a different taxon. The validity of this early taxon is questionable due to a lack of available material. The mosaic pattern of variation in Dikelocephalus mimics that documented at higher taxonomic levels in primitive libristomate trilobites, and helps explain difficulties in providing a workable taxonomy of primitive trilobites. Results caution proposition of evolutionary scenarios that do not take account of intraspecific variation. The recovery of dorsal shields of Dikelocephalus permits the first detailed reconstruction of the entire exoskeleton. The systematics of the genus is revised and twenty-five species are suppressed as junior synonyms of D. minnesotensis.

Download or read book Palaeoecology written by P.J. Brenchley and published by CRC Press. This book was released on 2023-07-14 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first palaeoecology book to focus on evolutionary palaeoecology, in both marine and terrestrial environments. Discusses reconstruction of the past ecological world at population, community and biogeographic levels. A well-illustrated and substantial volume giving accessible coverage of the full range of subjects within palaeoecology. Reviews and summarises all the major mass extinctions.

Download or read book The Ecology of the Cambrian Radiation written by Robert Riding and published by Columbia University Press. This book was released on 2001 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cambrian radiation was the explosive evolution of marine life that started 550,000,000 years ago. It ranks as one of the most important episodes in Earth history. This key event in the history of life on our planet changed the marine biosphere and its sedimentary environment forever, requiring a complex interplay of wide-ranging biologic and nonbiologic processes. The Ecology of the Cambrian Radiation offers a comprehensive and surprising picture of the Earth at that ancient time. The book contains contributions from thirty-three authors hailing from ten countries and will be of interest to paleontologists, geologists, biologists, and other researchers interested in the global Earth-life system.

Download or read book Ontogeny and Phylogeny of Early Cambrian Olenelloid Trilobites with Emphasis on the Late Dyeran Biceratopsidae written by Mark Webster and published by . This book was released on 2003 with total page 1126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fossils Phylogeny and Form written by Jonathan M. Adrain and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phylogenetic analysis and morphometrics have been developed by biologists into rigorous analytic tools for testing hypotheses about the relationships between groups of species. This book applies these tools to paleontological data. The fossil record is our one true chronicle of the history of life, preserving a set of macroevolutionary patterns; thus various hypotheses about evolutionary processes can be tested in the fossil record using phylogentic analysis and morphometrics. The first book of its type, Fossils, Phylogeny, and Form will be useful in evolutionary biology, paleontology, systematics, evolutionary development, theoretical biology, biogeography, and zoology. It will also provide a practical, researcher-friendly gateway into computer-based phylogenetics and morphometrics.

Download or read book Smithsonian Contributions to Paleobiology written by Smithsonian Institution and published by . This book was released on 1969 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Species and Speciation in the Fossil Record written by Warren D. Allmon and published by University of Chicago Press. This book was released on 2016-10-05 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: The literature of paleobiology is brimming with qualifiers and cautions about using species in the fossil record, or equating such species with those recognized among living organisms. Species and Speciation in the Fossil Record digs through this literature and surveys the recent research on species in paleobiology. In these pages, experts in the field examine what they think species are - in their particular taxon of specialty or more generally in the fossil record. They also reflect on what the answers mean for thinking about species in macroevolution. The first step in this approach is an overview of the Modern Synthesis, and paleobiology’s development of quantitative ways of documenting and analyzing variation with fossil assemblages. Following that, this volume’s central chapters explore the challenges of recognizing and defining species from fossil specimens, and show how with careful interpretation and a clear species concept, fossil species may be sufficiently robust for meaningful paleobiological analyses. Tempo and mode of speciation over time are also explored, exhibiting how the concept of species, if more refined, can reveal enormous amounts about the interplay between species origins and extinction and local and global climate change.

Download or read book Paleobiologic Aspects of Olenelloid Trilobites from the Uppermost Dyeran C shale Member of the Pioche Formation Nevada written by Mark Webster and published by . This book was released on 1999 with total page 528 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 2003 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Zoological Record written by and published by . This book was released on with total page 914 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bulletin written by Minnesota Geological Survey and published by . This book was released on 2000 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report of Investigations written by and published by . This book was released on 2008 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cambro Ordovician Studies written by J. R. Laurie and published by . This book was released on 2009 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Palaeobiology written by D. A. T. Harper and published by John Wiley & Sons. This book was released on 1999-07-09 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical Palaeobiology Computer-Based Modelling and Analysis of Fossils and their Distributions Edited by David A.T. Harper University of Copenhagen, Denmark Microcomputers have become an everyday part of the palaeobiologists tool-kit. Moreover, there is now a wide range of computer software available to handle all sorts of palaeontological data and problems. This book, aimed at final year undergraduates, graduate students and professional palaeontologists, biologists and geologists, brings together the many strands of contemporary palaeontology through the medium of numeracy. It provides a comprehensive review, with applications, of the many computer based techniques available for the analysis and modelling of palaeontological data. The first part of the book covers classical phenetic taxonomy through cladistics and the computer-generated reconstructions of fossils to actual models for fossil growth. This leads onto distribution analysis and modelling of fossils in time and space. Detailed stratigraphical distributions of fossils are described in quantitative terms together with the larger-scale patterns in the history of life itself, while palaeoecology, palynofacies, trace fossils and palaeogeography are all introduced through a spectrum of numerical algorithms. The majority of the studies are linked to specific software packages and many are illustrated with case histories. Although there are a number of books available on computer modelling and data analysis in geology, no study has integrated the two with such a range of palaeontological subject material.

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 1450 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transactions of the Royal Society of Edinburgh written by and published by . This book was released on 2001 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Beyond Heterochrony written by Miriam Zelditch and published by Wiley-Liss. This book was released on 2001-10-03 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heterochrony has been a dominant theme in the explosion of interest of evolution and development. This book explores beyond heterochrony for the links between evolutionary and developmental processes, as well as the origins of morphological diversity.