请输入您要查询的英文单词:

 

单词 placoderm
释义

placoderm

[ plak-uh-durm ]
/ ˈplæk əˌdɜrm /

noun

any of various extinct jawed fishes of the class Placodermi, dominant in seas and rivers during the Devonian Period and characterized by bony armored plates on the head and upper trunk.

Origin of placoderm

1855–60; <New Latin Placodermi name of the class, plural of placodermus, equivalent to placo- (<Greek; see placoid, -o-) + -dermus-derm

Words nearby placoderm

placing, plack, plackart, placket, placode, placoderm, placoid, plafond, plagal, plagal cadence, plage
Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for placoderm

  • Placoderm, plak′o-dėrm, adj. noting an order of fossil fishes having their skin covered with bony plates.

    Chambers's Twentieth Century Dictionary (part 3 of 4: N-R)|Various

British Dictionary definitions for placoderm

placoderm
/ (ˈplækəˌdɜːm) /

noun

any extinct bony-plated fishlike vertebrate of the class Placodermi, of Silurian to Permian times: thought to have been the earliest vertebrates with jaws

Word Origin for placoderm

C19: from Greek plac-, plax a flat plate + -derm
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for placoderm

placoderm
[ plăkə-dûrm′ ]

Any of various extinct fishes of the class Placodermi of the Silurian and Devonian Periods, characterized by bony plates of armor covering the head and flanks. The bodies of placoderms were spindle-shaped or flattened, and their skeletons were usually partially bony and included a cranium. Placoderms were the first group of fish to evolve jaws, but are not closely related to the jawed fish of today.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
随便看

 

英语词典包含192737条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。

 

Copyright © 2004-2022 Newdu.com All Rights Reserved
更新时间:2025/3/22 11:36:27