Suchosaurus

Suchosaurus (meaning "crocodile lizard") is as a spinosaurid theropod dinosaur from Cretaceous England, originally believed to be a genus of crocodile. The type material consists of teeth. Two species, S. cultridens and S. girardi have been named.

About 1820, Gideon Mantell acquired some spinosaurid teeth discovered near Cuckfield in the Wadhurst Clay of East Sussex, part of a lot with the present inventory number BMNH R36536. In 1822, he reported these, after an identification by William Clift, as belonging to crocodiles.[1] In 1824, the teeth were mentioned and illustrated by Georges Cuvier, representing the first illustration of a spinosaurid fossil.[2] In 1827 Mantell described additional teeth, pointing out the similarities to the crocodylian Teleosaurus and Gavialis.[3] One of these teeth is the present specimen BMNH R4415, others are part of BMNH R36536.

In 1841, Richard Owen named, based on BMNH R36536 as a syntype series, a subgenus Crocodylus (Suchosaurus) with as type species Crocodylus (Suchosaurus) cultridens.[4] The subgeneric name was derived from Greek σοῦχος, souchos, the name of the Egyptian crocodile god Sobek. This reflected the presumed taxonomic affinities; at the time Owen was not aware of the crocodile-like snouts of spinosaurids. The specific name is derived from Latin culter, "dagger", and dens, "tooth", in reference to the elongated form of the teeth. In 1842, Owen again mentioned the taxon as a subgenus,[5] subsequently he and other workers would use it as a full genus Suchosaurus. In 1842 and 1878 Owen referred some vertebrae to Suchosaurus,[6] but these likely belong to Ornithischia instead.[7] In 1884, Owen indicated a tooth as "Suchosaurus leavidens" in a caption,[8] this is usually seen as a lapsus calami because this species is not further mentioned.

In 1897, Henri-Émile Sauvage named a second species: Suchosaurus girardi, based on two jaw fragments (specimen MG324) and a tooth, found in Portugal by Paul Choffat. The specific name honours French geologist Albert Girard.[9] The tooth was considered lost but was rediscovered and in 2013 reported as specimen MNHN/UL.I.F2.176.1, part of remains recovered after a fire in 1978.[10]

During the nineteenth and most of the twentieth century, Suchosaurus was usually considered to have been some obscure crocodilian, perhaps belonging to the Pholidosauridae.[11] Single comparable teeth discovered in England were referred to the genus.[7] However, when publishing a redescription of Baryonyx in 1998, Angela Milner realised that the teeth of that spinosaurid dinosaur were extremely similar to those of Suchosaurus. In 2003, she suggested both genera represented one and the same animal.[12] An identity would imply the name Suchosaurus has priority. However, the Suchosaurus teeth are also indistinguishable from those of Cristatusaurus and Suchomimus, making it a indeterminate baryonychine.

The S. girardi material was reclassified by Eric Buffetaut as cf. Baryonyx walkeri in 2007.[13] Of the remaining species, S. cultridens, he affirmed that the holotype teeth strongly resembled those of Baryonyx walkeri. While there are some differences between the teeth, these may or may not represent individual variation among specimens, and he concluded that Suchosaurus may be a senior synonym of Baryonyx.[13]

Suchosaurus was considered a nomen dubium by Octávio Mateus et al. (2011).