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Aetiocetus is an extinct genus of baleen whale that lived 25 million years ago, in the Oligocene period. Its fossils have been found in the North Pacific,[1] around Oregon. It was first named by Douglas Emlong in 1966 and currently contains four species, A cotylalveus, A. polydentatus, A. tomitai, and A. weltoni.
Description Aetiocetus is a transitional fossil between early whales and modern whales, its blowhole being located halfway up its snout rather than at the top of its head.[2] It is also one of the earliest known baleen whales.[3] The genus, though more cranially reminiscent of archaic whales, with its pronounced snout and flat cranium,[4] had a loose jaw like later baleen whales.[3] Aetiocetus skulls have also shown that the animal bore a full set of teeth,[3][5] as well as baleen.[4][6] The skulls contain about forty-four teeth,[7] which consist of cusped molars, curved canines, and incisors.[4] Aetiocetus most likely fed on fish and crustaceans.[4] Douglas Emlong originally classified it in the extinct whale suborder Archaeoceti,[8][9] because of its teeth. However, when Van Valen analyzed it in 1968, he moved the genus to the suborder Mysticeti due to its derived pattern of bone telescoping.[9] Other genera in the same family, Aetiocetidae, include Ashorocetus, Chonecetus, Morawanocetus and Willungacetus.[10] Species - A. cotylalveus Emlong, 1966 (type species)
- A. polydentatus Sawamura, 1994
- A. tomitai Kimura & Barnes, 1994
- A. weltoni Barnes & Kimura, 1994 an analysis of this species revealed similar palatal nutrient foramina to those that house vessels that feed modern genera of Mysticeti.[6]
References Further reading - At the Water's Edge : Fish with Fingers, Whales with Legs, and How Life Came Ashore but Then Went Back to Sea by Carl Zimmer ISBN 0-684-83490-1
- Marine Mammals: Evolutionary Biology by Annalisa Berta, James L. Sumich, and Kit M. Kovacs
- In Search of Ancient Oregon: A Geological and Natural History by Ellen Morris Bishop
- Whales of the West Coast by David A. E. Spalding
- Encyclopedia of Marine Mammals by William F. Perrin, Bernd Wursig, and J. G.M. Thewissen
- Aquagenesis: The Origin and Evolution of Life in the Sea by Richard Ellis
External links es:Aetiocetus it:Aetiocetus jv:Aetiosetus ru:Aetiocetus zh:
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