Comparative fine structure of the Osteichthyan dermotrichia.

This study shows that camptotrichia constitute the only skeleton of the Dipnoan fins. Their fine structure is indeed quite different from the two other Osteichthyan dermotrichia, namely the actinotrichia and the lepidotrichia found simultaneously in the fin margin of both Actinopterygians and Crossopterygians fins. Although different from lepidotrichial bone, the fine structure of camptotrichia is more reminiscent of it than of the elastoidin-formed actinotrichia.