巴基鯨

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巴基鯨
化石時期: 早始新世
Pakicetus BW.jpg
保护状况
化石
科學分類
界: 動物界 Animalia
門: 脊索動物門 Chordata
綱: 哺乳動物綱 Mammalia
目: 鯨目 Cetacea
亞目: 古鯨亞目 Archaeoceti
科: 巴基鯨科 Pakicetidae
亞科: 巴基鯨亞科 Pakicetinae
屬: 巴基鯨屬 Pakicetus
種: 巴基鯨 P. inachus
二名法
Pakicetus inachus
Gingerich & Russell, 1981

巴基鯨(学名:Pakicetus),又名巴基斯坦鯨,已經絕種的古代哺乳動物,生活在陸地,形狀類似狼,屬於古鯨亞目,是現代鯨魚的前身,生存於始新世(5580-3390萬年前)的巴基斯坦,故此得名。發現化石的地層是特提斯洋的沿岸部份。

首先發現的巴基鯨化石是一個長頭顱骨,最初被認為是屬於中爪獸目,但因其內耳的特徵而確定是早期的鯨魚。[1]故此牠是已滅絕的陸上哺乳動物及現代鯨魚的過渡物種。

巴基鯨的完整骨骼於2001年發現,顯示了牠們主要生活在陸地上。巴基鯨約有的大小,外觀很像中爪獸目的动物。[2]

參考[编辑]

  1. ^ P. D. Gingerich & D. E. Russell. Pakicetus inachus, a new archaeocete (Mammalia, Cetacea) from the early-middle Eocene Kuldana Formation of Kohat (Pakistan). Univ. Mich. Contr. Mus. Paleont. 1981年, 25: 235–246. 
  2. ^ J. G. M. Thewissen, E. M. Williams, L. J. Roe and S. T. Hussain. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature. 2001年, 413: 277–281. 

The fossil consists of a complete skull of an archaeocyte, an extinct group of ancestors of modern cetaceans. Although limited to a skull, the Pakicetus fossil provides precious details on the origins of cetaceans. The skull is cetacean-like but its jawbones lack the enlarged space that is filled with fat or oil and used for receiving underwater sound in modern whales. Pakicetus probably detected sound through the ear opening as in land mammals. The skull also lacks a blowhole, another cetacean adaptation for diving. Other features, however, show experts that Pakicetus is a transitional form between a group of extinct flesh-eating mammals, the mesonychids, and cetaceans. It has been suggested that Pakicetus fed on fish in shallow water and was not yet adapted for life in the open ocean. It probably bred and gave birth on land.