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May 21, 2007 · Marine Mammal Diversity. Living groups of marine mammals vary greatly in their diversity. Rice (1998; Table 1 therein) reports that living Cetacea include 83 species in 39 genera; living Pinnipedia include 36 species in 21 genera; and Recent Sirenia include 5 species in 3 genera. Since then, several new species of cetaceans have been described ...
- Mark D. Uhen
- 2007
Mar 21, 2012 · This is an exciting time to study marine mammal evolution as many of the most important discoveries in this field have been made in the last 10-15 years, and there is no reason to expect that pace ...
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Apr 16, 2009 · Cetaceans (whales, dolphins, and porpoises) are an order of mammals that originated about 50 million years ago in the Eocene epoch. Even though all modern cetaceans are obligate aquatic mammals, early cetaceans were amphibious, and their ancestors were terrestrial artiodactyls, similar to small deer. The transition from land to water is documented by a series of intermediate fossils, many of ...
- J. G. M. Thewissen, Lisa Noelle Cooper, Lisa Noelle Cooper, John C. George, Sunil Bajpai
- 2009
The evolution of cetaceans is thought to have begun in the Indian subcontinent from even-toed ungulates (Artiodactyla) 50 million years ago (mya) and to have proceeded over a period of at least 15 million years. [2] Cetaceans are fully aquatic marine mammals belonging to the order Artiodactyla and branched off from other artiodactyls around 50 mya.
Indeed, life had been evolving and changing for more than 3 billion years—the majority of the planet's existence—before the first creatures made their way out of the water. The first ocean lifeforms were microscopic, so small they would be invisible to the naked eye. Later, bizarre and alien-like creatures reigned supreme.
The return to the sea: The evolution of marine mammals. : : : Both morphological and molecular data tell us that the ancestors of the marine mammals were terrestrial, and that their various marine lifestyles have evolved independently at least seven times! Each lineage shows shared as well as unique evolutionary solutions to the challenges of ...
Oct 18, 2012 · University of California Press, Berkeley, CA. 2012. 205 pp., $49.95 (cloth), $25.62 (Kindle). ISBN 9780520270572. Annalisa Berta leads readers through a vast range of topics regarding the evolution of marine mammals in Return to the Sea: The Life and Evolutionary Times of Marine Mammals. In this volume geared towards non-specialists (one might ...
