Moythomasia (named for James Alan Moy-Thomas)[1] is an extinct genus of early ray-finned fish from the Devonian period of Europe and Australia.

Moythomasia was a small freshwater fish, 9 centimetres (3.5 in) long.

It had relatively large eyes, presumably to find prey in murky water.

Its body was covered in specialized ganoid scales; the upper side of each scale sported a small pin that perfectly fit into the hollow lower side of the next scale.

This article about a prehistoric ray-finned fish is a stub.