请输入您要查询的英文单词:

 

单词 Bactritoid
释义

Bactritoid

英语百科

Bactritida

Bactritida is a small order of more or less straight-shelled (orthoconic) cephalopods that first appeared during the Emsian stage of the Devonian period (390 million years ago) and persisted until the Carnian stage of the Triassic period (235 million years ago). They are considered ancestors of the ammonoids, as well as of the coleoids (octopus, squid, cuttlefish, and the extinct belemnites).

随便看

 

英汉双解词典包含3607232条英汉词条,基本涵盖了全部常用单词的翻译及用法,是英语学习的有利工具。

 

Copyright © 2004-2022 Newdu.com All Rights Reserved
京ICP备09058993号 更新时间:2025/8/17 15:28:32