palaeoniscid

Member of a primitive order of freshwater ray-finned fish. They had a spindle-shaped body, scales of a characteristic structure known as ganoid, and a heterocercal (asymmetrical) tail. They lived from Devonian to Jurassic times, but were most abundant in the Carboniferous period.

Classification Palaeoniscids are in class Osteichthyes.

There are approximately 37 families in this group, with a wide distribution, fossils having been found in the British Isles, South Africa, Australia, and North America. The shape of the fishes suggests that they were fast swimming predators, initially freshwater with later members moving into the seas.

Cheirolepis canadensis, from the Upper Devonian era, is an example of the group.