Paraorthacodus is an extinct genus of shark. It a member of the family Paraorthacodontidae[1][2] (though it was formerly regarded as a member of the family Palaeospinacidae[3]), which is either placed in Hexanchiformes[2] or in Synechodontiformes.[1] It is known from over a dozen named species[4] spanning from the Early Jurassic[4] to the Paleocene,[4] or possibly Eocene.[3] Almost all members of the genus are exclusively known from isolated teeth, with the exception of P. jurensis from the Late Jurassic-Early Cretaceous of Europe, which is known from full body fossils from the Late Jurassic of Germany,[5] which suggest that juveniles had a robust body with a round head, while adults had large body sizes with a fusiform profile.[1] There was only a single dorsal fin towards the back of the body without a fin spine.[3] The dentition had teeth with a single large central cusp along with shorter lateral cusplets,[3] which where designed for clutching.[1] The teeth are distinguished from those of Synechodus by the lateral cusplets decreasing in size linearly away from the central cusp rather than exponentially as in Synechodus.[3]
| Paraorthacodus
| |
|---|---|
| |
| Paraorthacodus jurensis holotype specimen | |
| |
| Paraorthacodus jurensis full-body specimen | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Family: | †Paraorthacodontidae |
| Genus: | †Paraorthacodus Glückman, 1957 |
| Species | |
|
P. andersoni | |
 | This article about a prehistoric cartilaginous fish is a stub. You can help Wikipedia by expanding it. |
