NEW WHALE FROM THE EOCENE OF PAKISTAN AND THE ORIGIN OF CETACEAN SWIMMING

被引：105

作者：

GINGERICH, PD ^{[1
]}

RAZA, SM ^{[1
]}

ARIF, M ^{[1
]}

ANWAR, M ^{[1
]}

ZHOU, XY ^{[1
]}

机构：

[1] GEOL SURVEY PAKISTAN,PALEONTOL & STRATIG BRANCH,ISLAMABAD,PAKISTAN

来源：

NATURE | 1994年 / 368卷 / 6474期

关键词：

D O I：

10.1038/368844a0

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

MODERN whales (order Cetacea) are marine mammals that evolved from a land-mammal ancestor, probably a cursorial Palaeocene-Eocene mesonychid(1-3). Living whales are streamlined, lack external hind limbs, and all swim by dorsoventral oscillation of a heavily muscled tail(4,5). A steamlined rigid body minimizes resistance, while thrust is provided by a lunate horizontal fluke attached to the tail at a narrow base or pedicle(6). We describe here a new 46-47-million-year-old archaeocete intermediate between land mammals and later whales. It has short cervical vertebrae, a reduced femur, and the flexible sacrum, robust tail and high neural spines on lumbars and caudals required for dorsoventral oscillation of a heavily muscled tail. This is the oldest fossil whale described from deep-neritic shelf deposits, and it shows that tail swimming evolved early in the history of cetaceans.

引用

页码：844 / 847

页数：4