Ozarkian And Canadian Cephalopods Part Iii Longicones And Summary

Paleontology and Neontology of Cephalopods examines information that throws new light on the evolution of coleoids. This book is part of a multivolume work, The Mollusca, which attempts to provide comprehensive treatment of major areas of molluscan research. The Mollusca is intended to serve several disciplines—zoology, biochemistry, physiology, and paleontology. It will prove useful to researchers and to all others with interests in mollusks. The book begins with a review of the main features of cephalopod evolution. This is followed by separate chapters on the evolution of the gladius in coleoids; the buccal mass of Cephalopoda; beaks of living coleoid Cephalopoda; cephalopod hooks; statoliths of cephalopods; buoyancy and locomotion in recent cephalopods; and evolution of the cephalopod brain and cephalopod statocyst. Subsequent chapters deal with the photophore structure and evolution within the Enoploteuthinae; the interrelationships of genera within the Ommastrephidae; evolutionary pathways traversed by the cephalopod family Cranchiidae; the cephalopod fauna of the European Mediterranean; and the evolution of recent cephalopods.

The Early Palaeozoic was a critical interval in the evolution of marine life on our planet. Through a window of some 120 million years, the Cambrian Explosion, Great Ordovician Biodiversification Event, End Ordovician Extinction and the subsequent Silurian Recovery established a steep trajectory of increasing marine biodiversity that started in the Late Proterozoic and continued into the Devonian. Biogeography is a key property of virtually all organisms; their distributional ranges, mapped out on a mosaic of changing palaeogeography, have played important roles in modulating the diversity and evolution of marine life. This Memoir first introduces the content, some of the concepts involved in describing and interpreting palaeobiogeography, and the changing Early Palaeozoic geography is illustrated through a series of time slices. The subsequent 26 chapters, compiled by some 130 authors from over 20 countries, describe and analyse distributional and in many cases diversity data for all the major biotic groups plotted on current palaeogeographic maps. Nearly a quarter of a century after the publication of the ‘Green Book’ (Geological Society, London, Memoir12, edited by McKerrow and Scotese), improved stratigraphic and taxonomic data together with more accurate, digitized palaeogeographic maps, have confirmed the central role of palaeobiogeography in understanding the evolution of Early Palaeozoic ecosystems and their biotas.