Most rauisuchids have a crest on the illium called the supra-acetabular process that overlies the head of the femur, allowing them to have a "pillar-erect" stance.[4][5] As an early rauisuchid Vjushkovisaurus lacks this crest, but it does have a small thickening on the surface of the illium.[6] The humerus differs from other better known rauisuchids in that it is shorter and broader. However, it has been suggested that the only known humerus of Vjushkovisaurus may actually belong to an aetosaur.[7]
More recently, Nesbitt (2009) argued that Vjushkovisaurus represent most probably a valid non-archosaurian archosauriform. According to his analysis, the original diagnosis of Vjushkovisaurus by Ochev (1982) consisted of some of the plesiomorphies for Archosauriformes and characters with wide distributions throughout archosauriforms. For example, elongated anterior cervical vertebrae are present in the poposauroids, Yarasuchus, and in the non-archosaurian archosauriforms Proterosuchus and Guchengosuchus. Other features which are typically thought to be associated with skeletal pneumaticity, are also present in Guchengosuchus, Erythrosuchus, and in several archosaurs. Additionally, the shape and placement of the deltopectoral crests of the humerus of Vjushkovisaurus are typical of basal archosauriforms. The ectepicondylar groove on the humerus reported by Ochev is present in Prolacerta, Proterosuchus, phytosaurs, aetosaurs and several paracrocodylomorphs. Gower and Sennikov (2000) reported that the posterior cervical vertebrae bear well-defined facets for three-headed ribs. According to Nesbitt (2009), this trait is absent in Archosauria with the possible exception of Arizonasaurus and Poposaurus, but was used as a synapomorphy of Erythrosuchia in Parrish (1992) phylogenetic analysis.[3]
^ abGower, D.J.; Sennikov, A.G. (1997). "Sarmatosuchus and the early history of the Archosauria". Journal of Vertebrate Paleontology. 17 (1): 60–73. doi:10.1080/02724634.1997.10010954.
^Gower, D.J.; Sennikov, A.G. (2003). "Early archosaurs from Russia". In Benton, M.J.; Shishkin, M.A.; Unwin, D.M. (eds.). The Age of Dinosaurs in Russia and Mongolia. Cambridge: Cambridge University Press. pp. 140–159.
^Juul, L. (1994). "The phylogeny of basal archosaurs". Palaeontologica Africana. 31: 1–38.
^Sennikov, A.G. (1996). "Evolution of the Permian and Triassic tetrapod communities of Eastern Europe". Palaeogeography, Palaeoclimatology, Palaeoecology. 120 (3): 331–351. Bibcode:1996PPP...120..331S. doi:10.1016/0031-0182(95)00041-0.
