See text The Eugeneodontiformes, (also called Eugeneodontida) is an extinct and poorly known order of cartilaginous fishes.
They possessed "tooth-whorls" on the symphysis of either the lower or both jaws and pectoral fins supported by long radials.
[2] The eugeneodonts are named after paleontologist Eugene S. Richardson, Jr.[3] The group first appeared in the fossil record during the late Mississippian (Serpukhovian).
Members of the Eugeneodontiformes are further classified into different families, the most well-preserved members that have been discovered are commonly placed within the families Helicoprionidae ("spiral saws"), and Edestidae ("those which devour"), the former containing the genera Helicoprion, Sarcoprion, and Parahelicoprion, and the latter containing the genera Edestus, Lestrodus, and Metaxyacanthus.
All eugeneodonts are thought to have been obligate carnivores, with each genus having specialized feeding behaviors, territory ranges, and specific prey.