Sources
Help build the largest human-edited directory on the web.
Submit a site - Become an editor
Wikipedia. Licensed under the GNU Free Documentation License.
Are you an expert in this subject? Join the discussion and share your knowledge at Wikipedia.org.
Osteostraci
From Wikipedia, the free encyclopedia
 |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
 The group Cephalaspidomorphs is represented by Cephalaspis.
|
||||||||||
| Scientific classification | ||||||||||
|
||||||||||
|
|
||||||||||
|
Cephalaspida |
Class Osteostraci was a group of bony-armored jawless fish (ostracoderms), that lived in what is now North America, Europe and Russia from the Middle Silurian to Late Devonian.
Anatomically speaking, the osteostracans, especially the Devonian species, were among the most advanced of all known agnathans. This is due to the development of paired fins, and their complicated cranial anatomy. However, the osteostracans were more related to other agnathans than to jawed vertebrates as their inner ears are formed by two pairs of semicircular canals, similar to those of living lampreys, as opposed to the three pairs found in the inner ears of jawed vertebrates.
http://academic.emporia.edu/mooredwi/nathist/chap3.htm
Janvier, Philippe. Early Vertebrates Oxford, New York: Oxford University Press, 1998. ISBN 0-19-854047-7
Long, John A. The Rise of Fishes: 500 Million Years of Evolution Baltimore: The Johns Hopkins University Press, 1996. ISBN 0-8018-5438-5
 |
This article about a prehistoric fish is a stub. You can help Wikipedia by expanding it. |