Crossopterygii

Order of both living and fossil bony fish. They are sometimes called fringe- or lobe-finned fishes because of an extension of the flesh and internal skeleton into the paired fins. They have functional lungs and internal nostrils, and are closely related to the lungfishes. They are mainly Devonian and Carboniferous in age, but one group, the coelacanths are living.

Classification Crossopterygians comprise an order of the class Sarcopterygii.

The pointed teeth show labyrinthine infoldings of enamel, of particular interest because identical teeth occur in the primitive amphibians known as Labyrinthodonts. Land vertebrates probably arose from Crossopterygians.