Hybodontiformes

Hybodus (from , 'crooked' and 'tooth') is an extinct genus of hybodont. Numerous species have been assigned to Hybodus spanning a large period of time, and it is currently considered a wastebasket taxon that is 'broadly polyphyletic' and requires reexamination. It has been suggested that Hybodus sensu stricto only consists of two species, the type species H. reticulatus and H. hauffianus, both known from the Early Jurassic of Europe, with H. obtusus from the Middle-Late Jurassic of Europe possibly also being a true species of Hybodus.

Hybodontiformes, commonly called hybodonts, are an extinct group of shark-like cartilaginous fish (chondrichthyans) which existed from the late Devonian to the Late Cretaceous. Hybodonts share a close common ancestry with modern sharks and rays (Neoselachii) as part of the clade Euselachii. They are distinguished from other chondrichthyans by their distinctive fin spines and cephalic spines present on the heads of males. An ecologically diverse group, they were abundant in marine and freshwater environments during the late Paleozoic and early Mesozoic, but were rare in open marine environments

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

Asteracanthus (from , 'star' and , 'spine') is an extinct genus of hybodont, known from the Middle Jurassic (Bathonian) to the Early Cretaceous (Valanginian).

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.

Meristodonoides is an extinct genus of hybodont known from the mid-late Cretaceous, with potential records dating back to the Jurassic. It is one of a number of hybodont genera composed of species formerly assigned to Hybodus.