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class of fishes (fossil)
(Redirected from Osteostraci)

The Oststracoderms are a class of extinct fish. They were bony-armoured jawless fish, the Osteostraci ("bony shields"). They lived in what is now North America, Europe and Russia from the Middle Silurian to Upper Devonian. They were the first fish to use gills just for respiration.


Silurian to Devonian

Cephalaspis species.jpg
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Osteostraci
Lankester, 1868
Headshield of Laxaspis

Ostracoderms were the first fossil fish to be discovered. They were found in the 1830s in the Old Red Sandstone of Scotland. The genus Cephalaspis is quite a common fossil in these rocks.[1]


  1. Maisey, John G. 1996. Discovering fossil fishes. New York: Henry Holt & Company. p37
Fossil Cephalaspis