| Paraorthacodus Temporal range: | |
|---|---|
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| Paraorthacodus jurensis specimen SMNS 88987/1 | |
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| Paraorthacodus jurensis specimen BSPG 1996 I 31 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Family: | † Paraorthacodontidae |
| Genus: | † Paraorthacodus Glückman, 1957 |
| Species | |
P. andersoni | |
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 were 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]
