Rileyasuchus is a genus of phytosaur from the Rhaetian (Late Triassic) Magnesian Conglomerate of England. It has a confusing history, being associated with the taxonomy of Palaeosaurus and Thecodontosaurus, and being a replacement name for a preoccupied genus (Rileya, which had already been used by Ashmead, and Howard both in 1888 for a hymenopteran).[1][2]
History and taxonomy
In 1902, Friedrich von Huene named the new genus for two vertebrae and a humerus from deposits in Bristol.[3] He had recognized it as a phytosaur by 1908 (by which point a few Palaeosaurus species had been added to the genus).[4]
It seems to have sat unrecognized for most of the 20th century, except for 1961 when Oskar Kuhn renamed it from Rileya to Rileyasuchus.[5] Adrian Hunt in 1994 (doctoral dissertation) first suggested that it was a herrerasaurid, although this was never published.[6] Benton et al. (2000) indicated that the type specimen was actually a chimera composed of a phytosaur humerus and Thecodontosaurus vertebrae.[7] It is best regarded as a nomen dubium.
Rileya was named after palaeontologist and surgeon Henry Riley who helped to discover the first known fossils in Bristol in 1834.
Paleobiology
As a phytosaur, it would have been a semi-aquatic crocodile-like predator.
References
- ^ Howard, L.O. (1888). The chalcid genus Rileya. Canadian Entomology 20:191-195.
- ^ Ashmead, W.H. (1888). A revised generic table of the Euryrtominae, with descriptions of new species. Pt I. Entomol. Am. 4:41-43.
- ^ von Huene, F. (1902). Überischt über die Reptilien der Trias. Geologische und Paläontologie Abhandlungen, Neu Folge 8:97-156. [German]
- ^ von Huene, F. (1908). On phytosaurian remains from the Magnesian Conglomerate of Bristol (Rileya platyodon). Annals and Magazine of Natural History, series 8 1:228-230.
- ^ Kuhn, O. (1961). Die Familien der rezenten und fossilen Amphibien und Reptilien. Meisenbach:Bamberg, 79 p.
- ^ Hunt, A.P. (1994). Unpublished doctoral dissertation, discussed here
- ^ Benton, M.J, Juul, L., Storrs, G.W., and Galton, P.M. (2000). Anatomy and systematics of the prosauropod dinosaur Thecodontosaurus antiquus from the upper Triassic of southwest England. Journal of Vertebrate Paleontology 20(1):77-108.