请输入您要查询的字词:

 

单词 Coelacanthiformes
释义
Coelacanthiformes

Geology and Earth Sciences
  • Order of bony fish thought to have been extinct for 50 million years (since the end of the Mesozoic era) until the discovery of the coelacanth (Latimeria chalumnae) off S. Africa in 1938. Both fossil and living coelacanths are bulky marine fish with a diphycercal or tri-lobed tail fin; the second dorsal, anal, pectoral, and pelvic fins are very unusual as they are supported by movable stalks or lobes. The much smaller fossil species lived from the Devonian to the Cretaceous. They were initially freshwater fish, but in the Triassic marine representatives also evolved.


随便看

 

科学参考收录了60776条科技类词条,基本涵盖了常见科技类参考文献及英语词汇的翻译,是科学学习和研究的有利工具。

 

Copyright © 2000-2023 Sciref.net All Rights Reserved
京ICP备2021023879号 更新时间:2024/7/1 0:01:32