Chondrosteidae

Chondrosteus acipenseroides, fossil in Teylers Museum, Haarlem.

• Europe
• Central Asia

The Chondrosteidae are a family of extinct primitive bony fishes from the order of sturgeon species ( Acipenseriformes ). There are only two safe genera known Chondrosteus from the Lower Jurassic of Europe and Strongylosteus from the Lower Cretaceous of Central Asia. In a more generic, the 5 -meter-long Gyrosteus from the Jurassic of England, it might be a Chondrosteiden also.

Features

The Chondrosteidae were medium-sized to very large fish (0.5 to 3 meters), which had a plumper, gedrungeneren body than today's Sturgeons. Except for the caudal peduncle and the upper lobe of the caudal fin heterocerken her body was unbeschuppt. Lower Schwanzflossenlobus was relatively large, and is wider than the upper one. The head was broad, rostrum extended and somewhat pointed. The mouth was under constant. Dorsal, ventral and anal fins were sitting in the rear half of the body, the anal fin is still at an angle behind the dorsal fin.

System

The Chondrosteidae are the primitive fossil sister group of all extant sturgeon species.