Simbirskiasaurus
Introduction '''''Simbirskiasaurus''''' is an extinct genus of ichthyosaur from the Early Cretaceous (early Barremian) of Ulyanovsk Oblast, Russia. Its type specimen is '''YKM 65119''', a fragmentary skull and vertebral column.
Description Fischer ''et al''. give the diagnosis of ''Simbirskiasaurus'' as follows: "Platypterygiine ophthalmosaurid characterized by the following autapomorphies: external naris divided by a nasomaxillary pillar; posterior opening of the narial complex with anteroposteriorly constricted dorsal extension; deeply interdigitating prefrontal–lacrimal suture reminiscent of the basal neoichthyosaurian ''Temnodontosaurus platyodon'' (Conybeare, 1822); see Godefroit, 1993. ''Simbirskiasaurus birjukovi'' is also characterized by the following unique combination of features: subnarial process of the premaxilla reaches the posterior margin of the external naris (shared with ''Cryopterygius kristiansenae'' Druckenmiller ''et al''., 2012); elongated anterior process of the maxilla, reaching anteriorly the level of the nasal unlike in ''Aegirosaurus leptospondylus'' Bardet & Fernández, 2000 and ''Sveltonectes insolitus'' (Fischer ''et al''., 2011b); pres- ence of a supranarial process of the premaxilla shared with ''Platypterygius australis'' (McCoy, 1867), see Kear, 2005, and possibly ''Pervushovisaurus bannovkensis'' (Arkhangelsky, 1998b)."
Phylogeny The following cladogram shows a possible phylogenetic position of ''Simbirskiasaurus'' in Ophthalmosauridae according to the analysis performed by Zverkov and Jacobs (2020).
See also * List of ichthyosaurs* Timeline of ichthyosaur research
References