Lissodus

Lissodus is an extinct genus of hybodont. While fossils attributed to this genus are known spanning from the latest Devonian (Famennian) to the very end of the Cretaceous (Maastrichtian), others consider the genus to have a more narrow range, spanning from the Early Triassic to the end of the Early Cretaceous (Albian). Lissodus is often placed in the family Lonchidiidae, though other authors consider it incertae sedis within Hybodontiformes. Lonchidion has often been regarded as synonymous, but many recent authors consider it to be a distinct but closely related genus.

Description
Lissodus sensu lato (including Lonchidion) has been estimated to have had a body size range of 15-50 cm. Typical dental features of this genus include a single central cusp, base of teeth expanding towards the lingual side and riddled with vascular canals. The shape of the main cusp and large canal openings are similar to those of the Cassisodus margaritae although latter has cusplets on both sides of the crown. The low crowned teeth suggest that Lissodus was a bottom dweller that fed by crushing hard shelled organisms (durophagy).

Distribution
Remains of Lissodus sensu lato have been found worldwide in both marine and freshwater environments.

One tooth of indeterminate Lissodus species is known from the Tournaisian Laurel Formation, Australia.

Preserved skull and postcranial remains are known for the Early Triassic species L. cassangensis and L. africanus from Angola and South Africa respectively.

Species
Known species:


 * Lissodus africanus
 * Lissodus angulatus
 * Lissodus bartheli
 * Lissodus cassangensis
 * Lissodus cristatus
 * Lissodus guenneguesi
 * Lissodus hasleensis
 * Lissodus johnsonorum
 * Lissodus leiodus
 * Lissodus leiopleurus
 * Lissodus lepagei
 * Lissodus levis
 * Lissodus minimus
 * Lissodus wardi
 * Lissodus xiushuiensis