Undorosaurus

Undorosaurus Temporal range: Late Jurassic, 150.8–145.5 Ma PreЄ Є O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	†Ichthyosauria
Family:	†Ophthalmosauridae
Subfamily:	†Platypterygiinae Efimov, 1999
Genus:	†Undorosaurus Efimov, 1999
Species
U. gorodischensis Efimov, 1999 U. trautscholdi Arkhangelsky & Zverkov, 2014
Synonyms
Ophthalmosaurus gorodischensis – Maisch & Matzke, 2000

Undorosaurus is an extinct genus of ophthalmosaurid ichthyosaur known from western Russia.

Description

Undorosaurus was first known from the holotype UPM EP-II-20 (527), a partial three-dimensionally preserved skeleton which preserved partial skull. It was collected near the Volga river at Gorodische from the Epivirgatites nikitini ammonoid zone, dating to the Late Jurassic. A second species, U. trautscholdi was described by M.S. Arkhangelsky and N.G. Zverkov in 2014 from a partial left forefin found in the locality of Mnevniki, in the Moscow Oblast.

Maisch and Matzke (2000) regarded Undorosaurus to be a species of Ophthalmosaurus. However, Storrs et al. 2000 rejected this synonymy based on the tooth morphology of the specimen. Chris McGowan and Ryosuke Motani (2003) pointed out two noteworthy differences to Ophthalmosaurus, an incompletely fused ischiopubis and a remarkably strong dentition, and considered Undorosaurus to be a valid genus of ophthalmosaurid. Undorosaurus's validity is now accepted by most authors, even by Maisch (2010) who originally proposed the synonymy.

Etymology

Undorosaurus was named by Vladimir M. Efimov in 1999 and the type species is Undorosaurus gorodischensis. The specific name is named after Gorodische, the type locality of this taxon. U. trautscholdi is named in honor of the geologist H. Trautschold who collected and made the first description of the fossils of the holotype of the species.

See also

• List of ichthyosaurs
• Timeline of ichthyosaur research