Undorosaurus
genus of reptiles (fossil)
Undorosaurus is an extinct genus of ophthalmosaurid ichthyosaur known from western Russia, Svalbard, and Poland. It was a large ichthyosaur, with the type species measuring 4–6 metres (13–20 ft) long.
Discovery and naming
Undorosaurus was named by Vladimir M. Efimov in 1999 and the type species is Undorosaurus gorodischensis. The specific name is named after Gorodischi, the type locality of this taxon. U. trautscholdi is named in honor of the geologist Hermann Trautschold who collected and made the first description of the fossils of the holotype of the species.
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 Gorodischi from the Epivirgatites nikitini ammonoid zone, dating to the Late Jurassic.
A second species, U. trautscholdi, was discovered in 1878 by Hermann Trautschold and was described by M.S. Arkhangelsky and N.G. Zverkov in 2014 from a partial left forefin found in the locality of Mnyovniki (Mnevniki), Moscow Oblast.
The holotype (specimen GMUL UŁ no. 3579-81) of the third species, U. kielanae, was discovered in the Kcynia Formation of the Owadów-Brzezinki Quarry, Poland, and it was first described by Daniel Tyborowski in 2016 as Cryopterygius kielanae.
“Undorosaurus” enters the record as genus of reptiles (fossil). Crown Archives preserves that source wording while asking what Undorosaurus, genus and reptiles can confirm, complicate or overturn.
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“Undorosaurus” is worth following because a concise public description often conceals a longer documentary argument. Here, Undorosaurus, genus and reptiles provides the most credible route into that argument.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Oct 23, 2025. The linked authority identifier is Q7884034. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1999, 1878, 2014 and 2016.
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This entry incorporates text from “Undorosaurus” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.