Simbirskiasaurus

Simbirskiasaurus
Temporal range: Early Cretaceous, 130 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: †Ichthyosauria
Family: †Ophthalmosauridae
Subfamily: †Platypterygiinae
Genus: †Simbirskiasaurus
Ochev and Efimov, 1985
Species
  • S. birjukovi Ochev and Efimov, 1985 (Type)

Simbirskiasaurus is an extinct genus of ichthyosaur from the Early Cretaceous (early Barremian) of Ulyanovsk Oblast, Russia.[1][2] Its type specimen is YKM 65119, a fragmentary skull and vertebral column.[3]

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)]."[2]

Phylogeny

The following cladogram shows a possible phylogenetic position of Simbirskiasaurus in Ophthalmosauridae according to the analysis performed by Zverkov and Jacobs (2020).[4]

Ophthalmosauria
Ophthalmosaurinae
Platypterygiinae


See also

References

  1. ^ Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (entry on Reptilia)". Bulletins of American Paleontology. 364: 560. Retrieved 2008-09-28.
  2. ^ a b Valentin Fischer, Maxim S. Arkhangelsky, Darren Naish, Ilya M. Stenshin, Gleb N. Uspensky and Pascal Godefroit (2014) Simbirskiasaurus and Pervushovisaurus reassessed: implications for the taxonomy and cranial osteology of Cretaceous platypterygiine ichthyosaurs. Zoological Journal of the Linnean Society 171(4): 822–841. http://onlinelibrary.wiley.com/doi/10.1111/zoj.12158/abstract
  3. ^ Storrs, G. W., M. S. Arkhangel'skii and V. M. Efimov. 2000. Mesozoic marine reptiles of Russia and other former Soviet republics. pages 187-210 In Benton, M. J., M. A. Shiskin, D. M. Unwin and E. N. Kurochkin, (eds.), The Age of Dinosaurs in Russia and Mongolia, Cambridge University Press, Cambridge.
  4. ^ Nikolay G. Zverkov & Megan L. Jacobs (2021) [2020]. "Revision of Nannopterygius (Ichthyosauria: Ophthalmosauridae): reappraisal of the 'inaccessible' holotype resolves a taxonomic tangle and reveals an obscure ophthalmosaurid lineage with a wide distribution". Zoological Journal of the Linnean Society. 191 (1): 228–275. doi:10.1093/zoolinnean/zlaa028.


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