Undorosaurus

Source: Wikipedia, the free encyclopedia.

Undorosaurus
Temporal range:
Ma
Recosntructed skeleton
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: †Ichthyosauria
Family: †Ophthalmosauridae
Subfamily: †Platypterygiinae
Genus: †Undorosaurus
Efimov, 1999
Type species
†Undorosaurus gorodischensis
(Efimov, 1999)
Other species
  • †U. nessovi Efimov, 1999
  • †U. trautscholdi Arkhangelsky & Zverkov, 2014[2]
  • †U. kielanae Tyborowski, 2016[3]
Synonyms

Undorosaurus is an

ichthyosaur known from western Russia, Svalbard, and Poland.[1][4][2] It was a large ichthyosaur, with the type species measuring 4–6 metres (13–20 ft) long.[2]

Discovery and naming

Undorosaurus was named by Vladimir M. Efimov in

type locality of this taxon.[4] 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.[2]

Undorosaurus was first known from the

Volga river at Gorodischi from the Epivirgatites nikitini ammonoid zone, dating to the Late Jurassic.[4] 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 Mnyovniki (Mnevniki) [ru], Moscow Oblast.[2]

Classification

Maisch and Matzke (2000) regarded Undorosaurus to be a species of Ophthalmosaurus.[5] However, Storrs et al. 2000 rejected this synonymy based on the tooth morphology of the specimen.[6] 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.[7] Undorosaurus's validity is now accepted by most authors, even by Maisch (2010) who originally proposed the synonymy.[8][9][10]

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.[11]

Phylogeny

The following cladogram shows a possible phylogenetic position of Undorosaurus in Ophthalmosauridae according to the analysis performed by Zverkov and Jacobs (2020).[12]

Ophthalmosauria
Ophthalmosaurinae
Platypterygiinae

Brachypterygius extremus

Aegirosaurus leptospondylus

Muiscasaurus catheti

Leninia stellans

Sveltonectes insolitus

Athabascasaurus bitumineus

Platypterygius americanus

Acuetzpalin carranzai

Platypterygius sachicarum

Caypullisaurus bonapartei

Grendelius mordax

Grendelius alekseevi

Grendelius pseudoscythicus

Grendelius zhuravlevi

Undorosaurus kielanae

Undorosaurus nessovi

Undorosaurus gorodischensis

Platypterygius australis

Plutoniosaurus bedengensis

Simbirskiasaurus birjukovi

Platypterygius hercynicus

Sisteronia seeleyi

Platypterygius platydactylus

Maiaspondylus lindoei

See also

References

  1. ^ a b "†Undorosaurus Efimov 1999". Paleobiology Database. Fossilworks. Retrieved 17 December 2021.
  2. ^ a b c d e M.S. Arkhangelsky & N.G. Zverkov (2014). "On a new ichthyosaur of the genus Undorosaurus" (PDF). Proceedings of the Zoological Institute of the Russian Academy of Sciences. 318 (3): 187–196.
  3. doi:10.4202/app.00252.2016
    .
  4. ^ a b c Vladimir M. Efimov (1999). "A new family of Ichthyosaurs, the Undorosauridae fam. nov. from the Volgian stage of the European part of Russia". Paleontological Journal. 33 (2): 174–181.
  5. ^ Michael W. Maisch & Andreas T. Matzke (2000). "The Ichthyosauria". Stuttgarter Beiträge zur Naturkunde: Serie B. 298: 1–159.
  6. ISBN 9780521545822
    .
  7. ^ 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
  8. ^ Michael W. Maisch (2010). "Phylogeny, systematics, and origin of the Ichthyosauria – the state of the art" (PDF). Palaeodiversity. 3: 151–214.
  9. S2CID 45794618
    .
  10. S2CID 86036325
    .
  11. S2CID 91912834
    .
  12. doi:10.1093/zoolinnean/zlaa028
    .
Retrieved from "https://en.wikipedia.org/w/index.php?title=Undorosaurus&oldid=1192156341"