Triassic cartilaginous fish

Xenacanthiformes (or Xenacanthida) is an order or superorder of extinct shark-like chondrichthyans (cartilaginous fish) known from the Carboniferous to the Late Triassic. They were native to freshwater, marginal marine, and shallow marine habitats. Some xenacanths may have grown to lengths of . Most xenacanths died out at the end of the Permian in the End-Permian Mass Extinction, with only a few forms surviving into the Triassic.

Listracanthus is a genus of extinct chondrichthyan with uncertain affinities. Species of Listracanthus are known primarily from their tremendous, feather-like denticles, which range up to four inches in length. The denticles had a large main spine, from which secondary spines emanate from the sides, like the barbs of a feather or a comb. Listracanthus first appeared in late Carboniferous strata in North America, and eventually disappear from the fossil record some time during the Early Triassic.

Fadenia is an extinct genus of eugeneodontid holocephalian chondrichthyan from the Carboniferous Period of Missouri (United States), the Permian period of Greenland, and the Early Triassic epoch of British Columbia, Canada (Sulphur Mountain Formation).

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. Some authors have propos

Caseodus is an extinct genus of eugeneodont from the Carboniferous of what is now the Midwestern United States, and potentially the Early Triassic of what is now British Columbia, Canada. The genus contains two Carboniferous species, C. basalis and C. eatoni, which are differentiated by the anatomy of their teeth but are otherwise identical. A third species, C. varidentis, is known from the Early Triassic Sulphur Mountain Formation, but due to its wildly different skull and tooth morphology it is questionable if it belongs in the genus. The genus name is in honor of paleoichthyologist Gerard C

REDIRECT Hybodontiformes

Acrodus (from , 'high' and 'tooth') is an extinct genus of hybodont spanning from the Early Triassic to the Late Jurassic. (The Early Cretaceous species "Acrodus" nitidus affinity to the genus is questionable.) It was durophagous, with blunt, broad teeth designed for crushing and grinding. Some Middle Triassic species have been suggested to have grown to lengths of . Species are known from both marine and freshwater environments, with all Middle and Late Jurassic species only known from freshwater.

Strophodus is an extinct genus of durophagous hybodont known from the Triassic to Cretaceous. It was formerly confused with Asteracanthus.