Orodontiformes

Orodontiformes is an extinct group of cartilaginous fish, known from the Late Devonian and Carboniferous periods.

They are part of Euchondrocephali (Holocephali sensu lato), making their closest living relatives chimaeras.

Most members are only known from teeth, which are low and rounded, and designed for crushing prey (durophagy).

According to Ginter et al 2010, the teeth of Orodontiformes are distinguished by the following features:[1] euselachiantype bases; a low, usually pyramidal or conical median cusp; lateral cusps which are completely fused or with separate tips; the position of at least a few cusps before fusion distinguishable by the relative thickness of the crown or the pattern of ornamentation; the crown at least partly built of tubular dentine.The only known members of the Orodontiformes known from skeletal material are two species of Orodus, Orodus greggi and Orodus micropterygius from the Carboniferous of North America.

[1] Ginter et al. 2010 divided up Orodontiformes into two families, Orodontidae, and Leiodontidae, the latter being distinguished from the former by lacking ornamentation on the tooth crown (with ridges being present on the crowns of orodontid teeth), and a typically pointed median cusp.