Definitions for ostracodermˈɒs trə koʊˌdɜrm

This page provides all possible meanings and translations of the word ostracoderm

Princeton's WordNet

  1. ostracoderm(noun)

    extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoic

Freebase

  1. Ostracoderm

    Ostracoderms refers to the armored jawless fishes of the Paleozoic. The term does not often appear in classifications today because it is paraphyletic or polyphyletic, and has no phylogenetic meaning. However, the term is still used as an informal way of loosely grouping together the armored jawless fishes. An innovation of ostracoderms was the use of gills not for feeding, but exclusively for respiration. Earlier chordates with gills used them for both respiration and feeding. Ostracoderms had separate pharyngeal gill pouches along the side of the head, which were permanently open with no protective operculum. Unlike invertebrates that use ciliated motion to move food, ostracoderms used their muscular pharynx to create a suction that pulled small and slow moving prey into their mouths. The first fossil fishes that were discovered were ostracoderms. The Swiss anatomist Louis Agassiz received some fossils of bony armored fish from Scotland in the 1830s. He had a hard time classifying them as they did not resemble any living creature. He compared them at first with extant armored fish such as catfish and sturgeons but later realizing that they had no movable jaws, classified them in 1844 into a new group "ostracoderms" which means "shell-skinned".

Translation

Find a translation for the ostracoderm definition in other languages:

Select another language:

Discuss these ostracoderm definitions with the community:

Word of the Day

Would you like us to send you a FREE new word definition delivered to your inbox daily?

Please enter your email address:     


Citation

Use the citation below to add this definition to your bibliography:

Style:MLAChicagoAPA

"ostracoderm." Definitions.net. STANDS4 LLC, 2015. Web. 23 May 2015. <http://www.definitions.net/definition/ostracoderm>.

Are we missing a good definition for ostracoderm? Don't keep it to yourself...

Nearby & related entries:

Alternative searches for ostracoderm:

Thanks for your vote! We truly appreciate your support.