Undorosaurus
{{Short description|Extinct genus of reptiles}}
{{automatic taxobox
| fossil_range = Late Jurassic,{{cite web |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=173203 |title=†Undorosaurus Efimov 1999 |work=Paleobiology Database |publisher=Fossilworks |access-date=17 December 2021}} {{Fossil range|150.8|145.5}}
| image = Ундорозавр (Ихтиозавр (Ichthyopterygia)) Музей палеонтологии. Ундоры. Ульяновская обл. Ноябрь 2013 - panoramio.jpg
| image_caption = Reconstructed skeleton of U. gorodischensis
| taxon = Undorosaurus
| authority = Efimov, 1999
| type_species = {{extinct}}Undorosaurus gorodischensis
| type_species_authority = (Efimov, 1999)
| subdivision_ranks = Other species
| subdivision = *{{extinct}}U. nessovi Efimov, 1999
- {{extinct}}U. trautscholdi Arkhangelsky & Zverkov, 2014{{cite journal |author=M.S. Arkhangelsky |author2=N.G. Zverkov |name-list-style=amp |year=2014 |title=On a new ichthyosaur of the genus Undorosaurus |journal=Proceedings of the Zoological Institute of the Russian Academy of Sciences |volume=318 |issue=3 |pages=187–196 |url=http://www.zin.ru/journals/trudyzin/doc/vol_318_3/TZ_318_3_Arkhangelsky.pdf }}
- {{extinct}}U. kielanae Zverkov & Efimov, 2019
| synonyms = *Cryopterygius kielanae Tyborowski, 2016{{cite journal |author=Daniel Tyborowski |year=2016 |title=A new ophthalmosaurid ichthyosaur from the Late Jurassic of Owadów-Brzezinki Quarry, Poland |journal=Acta Palaeontologica Polonica |volume=61 |issue=4 |pages=791–803|doi=10.4202/app.00252.2016 |doi-access=free }}
- Cryopterygius kristiansanae? Druckenmiller et al., 2012
- Ophthalmosaurus gorodischensis Maisch & Matzke, 2000
}}
Undorosaurus is an extinct genus of ophthalmosaurid ichthyosaur known from western Russia, Svalbard, and Poland.{{cite journal |author=Vladimir M. Efimov |year=1999 |title=A new family of Ichthyosaurs, the Undorosauridae fam. nov. from the Volgian stage of the European part of Russia |journal=Paleontological Journal |volume=33 |issue=2 |pages=174–181 }} It was a large ichthyosaur, with the type species measuring {{convert|4|-|6|m|ft}} long.
Discovery and naming
File:Cryopterygius skull bones.jpg
Undorosaurus was named by Vladimir M. Efimov in 1999 and the type species is Undorosaurus gorodischensis. The specific name is named after {{ill|Gorodischi|ru|Городищи (Ульяновский район)}}, 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 TrautscholdTrautschold, H. (1879). Uber eine Ichthyosaurus-Flosse aus dem Moskauer Kimmeridge. Zapisky Imperatorskogo Sankt-Peterburgskogo Mineralogicheskogo Obshestva. Ser. 2, 14: 168–173 and was described by M.S. Arkhangelsky and N.G. Zverkov in 2014 from a partial left forefin found in the locality of {{ill|Mnyovniki (village)|lt=Mnyovniki (Mnevniki)|ru|Мнёвники (бывшая деревня)}}, 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. C. kielanae was moved to Undorosaurus by Zverkov & Efimov (2019).
Classification
File:Undorosaurus kielanae forefin.jpg
Maisch and Matzke (2000) regarded Undorosaurus to be a species of Ophthalmosaurus.{{cite journal |author=Michael W. Maisch |author2=Andreas T. Matzke |name-list-style=amp |year=2000 |title=The Ichthyosauria |url=https://www.biodiversitylibrary.org/item/278993#page/351/mode/1up |journal=Stuttgarter Beiträge zur Naturkunde: Serie B |volume=298 |pages=1–159 }} However, Storrs et al. 2000 rejected this synonymy based on the tooth morphology of the specimen.{{cite book |last=Storrs |first=Glenn W. |author2=Vladimir M. Efimov |author3=Maxim S. Arkhangelsky |name-list-style=amp |year=2000 |chapter=Mesozoic marine reptiles of Russia and other former Soviet republics |title=The Age of Dinosaurs in Russia and Mongolia |editor1=Benton, M.J. |editor2=Shishkin, M.A. |editor3=Unwin, D.M. |publisher=Cambridge University Press |location=Cambridge |pages=140–159 |isbn=9780521545822}} 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.McGowan C, Motani R. 2003. Ichthyopterygia. – In: Sues, H.-D. (ed.): Handbook of Paleoherpetology, Part 8, Verlag Dr. Friedrich Pfeil, 175 pp., 101 figs., 19 plts; München Undorosaurus's validity is now accepted by most authors, even by Maisch (2010) who originally proposed the synonymy.{{cite journal |author=Michael W. Maisch |year=2010 |title=Phylogeny, systematics, and origin of the Ichthyosauria – the state of the art |url=http://www.palaeodiversity.org/pdf/03/Palaeodiversity_Bd3_Maisch.pdf |journal=Palaeodiversity |volume=3 |pages=151–214 }}{{cite journal |last=Fischer |first=V. |author2=A. Clement |author3=M. Guiomar |author4=P. Godefroit |name-list-style=amp |year=2011 |title=The first definite record of a Valanginian ichthyosaur and its implications on the evolution of post-Liassic Ichthyosauria |journal=Cretaceous Research |volume=32 |issue=2 |pages=155–163 |doi=10.1016/j.cretres.2010.11.005 |hdl=2268/79923 |s2cid=45794618 |url= https://orbi.uliege.be/handle/2268/79923}}{{cite journal |last=Fischer |first=V. |author2=Masure, E. |author3=Arkhangelsky, M.S. |author4= Godefroit, P. |name-list-style=amp |year=2011 |title=A new Barremian (Early Cretaceous) ichthyosaur from western Russia |journal=Journal of Vertebrate Paleontology |volume=31 |issue=5 |pages=1010–1025 |doi=10.1080/02724634.2011.595464 |hdl=2268/92828 |s2cid=86036325 |url=https://orbi.uliege.be/handle/2268/92828 }}
Zverkov & Efimov (2019) considered the genus Cryopterygius to be a junior synonym of the genus Undorosaurus. The authors considered the type species of the former genus, C. kristiansenae, to be synonymous with Undorosaurus gorodischensis; second species of Cryopterygius, C. kielanae, was tentatively maintained by the authors as a distinct species within the genus Undorosaurus.{{cite journal |author1=Nikolay G. Zverkov |author2=Vladimir M. Efimov |name-list-style=amp |year=2019 |title=Revision of Undorosaurus, a mysterious Late Jurassic ichthyosaur of the Boreal Realm |journal=Journal of Systematic Palaeontology |volume=17 |issue=14 |pages=963–993 |doi=10.1080/14772019.2018.1515793 |s2cid=91912834 |url=https://figshare.com/articles/Revision_of_i_Undorosaurus_i_a_mysterious_Late_Jurassic_ichthyosaur_of_the_Boreal_Realm/7624868 }}
=Phylogeny=
The following cladogram shows a possible phylogenetic position of Undorosaurus in Ophthalmosauridae according to the analysis performed by Zverkov and Jacobs (2020).{{cite journal |author1=Nikolay G. Zverkov |author2=Megan L. Jacobs |name-list-style=amp |orig-year=2020 |title=Revision of Nannopterygius (Ichthyosauria: Ophthalmosauridae): reappraisal of the 'inaccessible' holotype resolves a taxonomic tangle and reveals an obscure ophthalmosaurid lineage with a wide distribution |journal=Zoological Journal of the Linnean Society |volume=191 |issue=1 |year=2021 |pages=228–275 |doi=10.1093/zoolinnean/zlaa028}}
{{clade
|label1=Ophthalmosauria
|1={{clade
|1={{clade
|label1=Ophthalmosaurinae
|1={{clade
|1={{clade
|1={{clade
|1={{clade
|2={{clade
|2={{clade
}}
}}
}} }} }}
|2={{clade
|1={{clade
|2={{clade
|1={{clade
|2={{clade
|2=Nannopterygius saveljeviensis
}}
}}
|2={{clade
|1={{clade
|2={{clade
|2=Arthropterygius thalassonotus
|3={{clade
}}
}}
}}
}}
}}
}}
}}
}}
|label2=Platypterygiinae
|2={{clade
|1={{clade
|2=Aegirosaurus leptospondylus
|3={{clade
|2={{clade
|2={{clade
|2={{clade
|2={{clade
|2={{clade
|1={{clade
}}
|2={{clade
|1={{clade
|1={{clade
}}
|2={{clade
|1={{clade
|1={{clade
|1=Undorosaurus kielanae
|2={{clade
|1=Undorosaurus nessovi
|2=Undorosaurus gorodischensis
}}
}}
}}
}}
}}
|3={{clade
|2={{clade
|5=Platypterygius platydactylus
}}
}}
}}
}}
}} }} }} }} }} }} }} }} }} }}
=Cryopterygius=
File:Undorosaurus Skeleton.jpg of C. kristiansanae]]
Cryopterygius (meaning 'frozen fin' in Greek) is a dubious extinct genus of ophthalmosaurid ichthyosaur known from the Agardhfjellet Formation of Norway. One species was recognised: C. kristiansenae.{{cite journal |author1=Patrick S. Druckenmiller |author2=Jørn H. Hurum |author3=Espen M. Knutsen |author4=Hans Arne Nakrem |year=2012 |title=Two new ophthalmosaurids (Reptilia: Ichthyosauria) from the Agardhfjellet Formation (Upper Jurassic: Volgian/Tithonian), Svalbard, Norway |journal=Norwegian Journal of Geology |volume=92 |issue=2–3 |pages=311–339 |issn=1502-5322}} [http://www.geologi.no/images/njg/2012/2-3/NJG_2_3_2012_17_Druckenmiller_etal_Scr.pdf Low resolution pdf] {{webarchive|url=https://web.archive.org/web/20150924021821/http://www.geologi.no/images/njg/2012/2-3/NJG_2_3_2012_17_Druckenmiller_etal_Scr.pdf|date=2015-09-24}} [http://www.geologi.no/images/njg/2012/2-3/NJG_2_3_2012_17_Druckenmiller_etal_Pr.pdf High resolution pdf] {{webarchive|url=https://web.archive.org/web/20150924021801/http://www.geologi.no/images/njg/2012/2-3/NJG_2_3_2012_17_Druckenmiller_etal_Pr.pdf|date=2015-09-24}}
The holotype, PMO 214.578, consists of a single, but largely complete specimen from the Slottsmøya Member of the Agardhfjellet Formation that was excavated between 2004 and 2012. Druckenmiller et al. (2012) subsequently named and described C. kristiansenae on the basis of this specimen. It has been suggested that C. kristiansenae may also be synonymous with Undorosaurus.{{Cite journal |last1=Miedema |first1=Feiko |last2=Bastiaans |first2=Dylan |last3=Scheyer |first3=Torsten M. |last4=Klug |first4=Christian |last5=Maxwell |first5=Erin E. |date=2024-03-16 |title=A large new Middle Jurassic ichthyosaur shows the importance of body size evolution in the origin of the Ophthalmosauria |journal=BMC Ecology and Evolution |volume=24 |issue=1 |pages=34 |doi=10.1186/s12862-024-02208-3 |issn=2730-7182 |pmc=10944604 |pmid=38493100 |doi-access=free}}
A second species, C. kielanae, was found in the Kcynia Formation from the Late Jurassic of Poland.{{cite journal |author=Daniel Tyborowski |year=2016 |title=A new ophthalmosaurid ichthyosaur from the Late Jurassic of Owadów-Brzezinki Quarry, Poland |journal=Acta Palaeontologica Polonica |volume=in press |doi=10.4202/app.00252.2016 |doi-access=free}} It has since been synonymised with Undorosaurus and was found to be a species of Undorosaurus (U. kielanae).
See also
{{portal|Paleontology|Russia}}
References
{{Reflist|2}}
{{Ichthyosauria|Parvipelvia}}
{{Taxonbar|from=Q7884034|from2=Q5190548}}
Category:Extinct animals of Russia
Category:Late Jurassic ichthyosaurs