Origin and Early Evolution of the Metazoa


Book Description

Several years ago, we realized that the most prominent ideas that had been ex pressed about the origin and early evolution of the Metazoa seemed to have been developed chiefly by zoologists using evidence from modern species without reference to the fossil record. Paleontologists had, in fact, put forth their own ideas but the zoological and the paleontological evidence were about the problem, seldom considered together, especially by zoologists. We believed that the paleon tological documentation of the first Metazoa was too scattered, too obscure to Western readers, and much of it too recent to have been readily available to our colleagues in zoology. Whether or not that was entirely true, we thought that a single volume reviewing the fossil record of the earliest Metazoa would be useful to many in both paleontology and zoology, especially since so much new informa tion has been developed in the last few years. Some of this information has been summarized in general articles recently, but an overview of most of the field does not exist. We therefore organized this book in five parts so that the evidence could be placed in perspective and summarized and inferences made from it. Part I intro duces the previous hypotheses that have been proposed for the origin and early radiation of Metazoa. Part II consists of two summary chapters that set the sedi mentological, geochemical, and biological background to the known radiations of Metazoa.




The Garden of Ediacara


Book Description

Including twenty-two photographs and more than fifty drawings of these strikingly beautiful early life forms, this book presents a mesmerizing documentary of a major scientific discovery: the oldest animal fossils ever discovered.







The Late Triassic World


Book Description

This volume presents the latest science on all significant geological and paleontological aspects of the Earth during the Late Triassic Period. Rather than presenting a collection of narrowly focused research papers, the volume consists of a series of peer-reviewed chapters on specific aspects of the Late Triassic world (e.g., tectonics, magmatism, paleobotany, climate, etc.), all authored by experts in the subject of their respective chapters. Each chapter reviews and summarizes the latest findings in these fields and also includes a review of the pertinent literature. The author list is very broadly international and forms a veritable who’s who of expertise in these fields. The book is loosely organized to present the physical aspects of Earth during the Late Triassic at the outset, followed by the paleontological aspects. The latter section is further organized to present the record of the marine environment first before moving onto land, with fauna followed by flora. The volume closes with a review of the end-Triassic extinctions.







Canadian Inland Seas


Book Description

The various chapters of this book have been written by researchers who are still working in the Canadian Inland Seas region. The chapters synthesize what is known about these seas, yet much still is to be learnt. It is hoped that this collection of information will serve as a springboard for future, much needed, studies in this fascinating, diverse region, and will stimulate comparative analyses with other subarctic and arctic basins of the world. The Canadian Inland Seas are the only remnants, albeit cold, of the ancient cratonic marine basins which occupied central North America throughout the Paleozoic and part of the Mesozoic. Precambrian rocks and gently dipping Paleozoic sedimentary rocks underlie the seas. The area is also close to the centers of Pleistocene glaciations. The coastal areas represent an emerged landscape of the post-glacial Tyrrell sea, as the region has been isostatically uplifted to about 350 meters since glacial times. A total of 56 fish species inhabit Hudson Bay and James Bay. Seals, whales and one of the largest and southernmost populations of polar bears inhabit the seas as well. The coastal areas are important habitats for migratory bird populations, some of which migrate from as far away as Southern Argentina.The ostic environment has preserved these regions relatively unchanged by man, with only a major harbour at Churchill, Manitoba, which is active for part of the year, and a second large, rail-terminal settlement in the south at Moosonee, Ontario. A few, small, native Indian and Inuit villages dot the coasts. The seas are being affected indirectly by the damming of rivers for the generation of hydroelectric power, and by drainage diversions towards the man-made reservoirs. A major project is being completed in Quebec east of James Bay, but other rivers in Ontario and Manitoba have been dammed as well. Undoubtedly freshwater is one of the more important resources of the area, however its exploitation needs careful thought because of the possible long-range effects on the environment, particularly the coastal marshes, which sustain much of the eastern American intercontinental migratory avifauna. Other resources occur in the regions, primarily minerals and perhaps petroleum. For the most part however, such resources remain to be discovered.