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''Dorudon'' ("Spear-Tooth") is a genus of extinct basilosaurid ancient whales that lived alongside ''Basilosaurus'' , in the Eocene. They were about long and fed on small fish and mollusks. ''Dorudon'' lived in warm seas around the world. Fossils have been found along the former shorelines of the Tethys Sea in present-day Egypt and Pakistan, as well as in the United States, New Zealand, and Western Sahara.〔 ==Taxonomic history== described ''Dorudon serratus'' based on a fragmentary maxilla and a few teeth found in South Carolina. He concluded that the teeth must have belonged to a mammal since they were two-rooted, that they must have been teeth from a juvenile since they were hollow, and also noted their similarity to the teeth then described for ''Zeuglodon'' (=''Basilosaurus''). When exploring the type locality, Gibbes discovered a lower jaw and twelve caudal vertebrae, which he felt obliged to assign to ''Zeuglodon'' together with his original material. Gibbes concluded that ''Dorudon'' were juvenile ''Zeuglodon'' and consequently withdrew his new genus. He did however allow Louis Agassiz at Harvard to examine his specimens, and the Swiss professor replied that these were neither teeth of a juvenile nor those of ''Zeuglodon'', but of a separate genus just as Gibbes had first proposed.〔; 〕 described ''Prozeuglodon atrox'' (="Proto-''Basilosaurus''") based on a nearly complete skull, a dentary, and three associated vertebrae presented to him by the Geological Museum of Cairo.〔 , however, realized that Andrews' specimen was a juvenile, and, he assumed, the same species as ''Zeuglodon isis'', described by Andrews 1906. Kellogg also realized that the generic name ''Zeuglodon'' was invalid and therefore recombined it ''Prozeuglodon isis''. Since then many specimens have been referred to ''Prozeuglodon atrox'', including virtually every part of the skeleton, and it has become obvious that it is a separate genus, not a juvenile "Proto-''Zeuglodon''".〔 Kellogg placed several of the species of ''Zeuglodon'' described from Egypt in the early 20th century (including ''Z. osiris'', ''Z. zitteli'', ''Z. elliotsmithii'', and ''Z. sensitivius'') in the genus ''Dorudon''. synonymized these four species and grouped them as ''Saghacetus osiris''.〔 The current taxonomic status of ''Dorudon'' is based on 's revision of ''Dorudon'' and detailed description of ''D. atrox''. Before this, the taxonomy of ''Dorudon'' was in disarray and based on a limited set of specimens. ''D. atrox'' is known from Egypt,〔. Retrieved July 2013.〕 ''D. serratus'' from Georgia and South Carolina in the United States.〔. Retrieved July 2013.〕 The type species ''D. serratus'' was, and still is, based solely on two partial maxillae with a few teeth, cranial fragments, and a dozen vertebrae with some additional material, collected but not described by Gibbes, and referred to the type species. Before Uhen 2004, ''D. atrox'' was based solely on Andrews holotype skull, lower jaw, and the vertebrae he referred to it, but is now the best known archaeocete species.〔 The two species of ''Dorudon'' differ from other members of Dorudontinae mainly in size: they are considerably larger than ''Saghacetus'' and slightly larger than ''Zygorhiza'', but also differ from both these genera in dental and/or cranial morphology. The limited known material for ''D. serratus'' makes it difficult to compare the two species of ''Dorudon''. placed ''D. atrox'' in the same genus as ''D. serratus'' because of similarities in size and morphology, but kept them as separate species because of differences in dental morphology. Even-though ''D. serratus'' is the type species, the description of ''Dorudon'' is largely based on ''D. atrox'' because of its completeness. The cranial morphology of ''D. atrox'' makes it distinct from all other archaeocetes. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dorudon」の詳細全文を読む スポンサード リンク
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