''Gyroptychius'' is an extinct genus of

osteolepiform Osteolepiformes, also known as Osteolepidida, is a group of prehistoric lobe-finned fishes which first appeared during the Devonian period. The order contains the families Canowindridae, Megalichthyidae, Osteolepididae and Tristichopteridae. Th ...

lobe-finned fish Sarcopterygii (; ) — sometimes considered synonymous with Crossopterygii () — is a taxon (traditionally a class or subclass) of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass includi ...

from the

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

period. ''Gyroptychius'' was a fast riverine predator with an elongated body about long. As its eyes were relatively small, it is presumed to have hunted by smell rather than sight. ''Gyroptychius'' had short jaws which gave it a powerful bite. All its fins except the

pectorals Pectoral may refer to: * The chest region and anything relating to it. * Pectoral cross, a cross worn on the chest * a decorative, usually jeweled version of a gorget * Pectoral (Ancient Egypt), a type of jewelry worn in ancient Egypt * Pectoralis ...

were moved to the back to the body, increasing the power of the tail while swimming.

References

Prehistoric lobe-finned fish genera Megalichthyiforms Devonian bony fish Devonian fish of Europe {{paleo-lobefinned-fish-stub