Plutoniosaurus

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Plutoniosaurus
Temporal range: Early Cretaceous,
~135–130  Ma
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Plutoniosaurus

Efimov, 1997
Binomial name
Plutoniosaurus bedengensis
Efimov, 1997
Synonyms

Plutoniosaurus is an extinct genus of ophthalmosaurid ichthyosaur of uncertain validity from the Early Cretaceous (late Hauterivian) of the vicinity of Ulyanovsk, European Russia.

Contents

Taxonomy

Plutoniosaurus was named by Vladimir Efimov in 1997 based on the holotype specimen UPM 2/740, a partial skeleton containing the skull, the shoulder girdle, forelimbs and vertebrae. The generic name is derived from the Ulyanovsk Regional Young Paleontologists Club that was nicknamed Plutonia. The specific name refers to the village of Novaya Beden’ga, the site of discovery on the right bank of the Volga.

In 1999, Maxim Arkhangel'skii synonymized the genus with Platypterygius , [1] as did Michael Maisch and Andreas Matzke in 2000. [2] :82 While agreeing with the synonymy, Christopher McGowan and Ryosuke Motani considered P. bedengensis to be a nomen dubium within the genus in 2003, too poorly known to identify as a distinct species. [3] :136 In 2016, Valentin Fischer and colleagues considered the original description was too vague to confidently distinguish the genus and noted that the illustrations did not always match the written description. They thus regarded Plutoniosaurus bedengensis as a species inquirenda , while noting the possibility that it is the same species as the nearly coeval Simbirskiasaurus from the same region. [4]

Phylogeny

Zverkov and Efimov (2019) recovered Plutoniosaurus in a polytomy with the type species of Platypterygius and Leninia . [5] The following cladogram shows a possible phylogenetic position of Plutoniosaurus in Ophthalmosauridae according to the analysis performed by Zverkov and Jacobs (2020). [6]

Ophthalmosauria
Ophthalmosaurinae
Platypterygiinae

See also

Related Research Articles

<i>Ophthalmosaurus</i> Extinct genus of reptiles

Ophthalmosaurus is a genus of ichthyosaur known from the Middle-Late Jurassic. Possible remains from the earliest Cretaceous, around 145 million years ago, are also known. It was a relatively medium-sized ichthyosaur, measuring 4 m (13 ft) long and weighing 940 kg (2,070 lb). Named for its extremely large eyes, it had a jaw containing many small but robust teeth. Major fossil finds of this genus have been recorded in Europe with a second species possibly being found in North America.

Platypterygius is a historically paraphyletic genus of platypterygiine ichthyosaur from the Cretaceous period. It was historically used as a wastebasket taxon, and most species within Platypterygius likely are undiagnostic at the genus or species level, or represent distinct genera, even being argued as invalid. While fossils referred to Platypterygius have been found throughout different continents, the holotype specimen was found in Germany.

<i>Caypullisaurus</i> Extinct genus of reptiles

Caypullisaurus is an extinct genus of platypterygiine ophthalmosaurid ichthyosaur from the Late Jurassic to the Early Cretaceous of Argentina. Its holotype was collected from the Vaca Muerta Formation of Cerro Lotena, Neuquen, dating to the early Tithonian stage of the Late Jurassic, about 150 million years ago. Caypullisaurus was first named by Marta Fernández in 1997 and the type species is Caypullisaurus bonapartei. It was a large ichthyosaur, measuring about 7 m (23 ft) long.

<span class="mw-page-title-main">Ophthalmosauridae</span> Extinct family of reptiles

Ophthalmosauridae is an extinct family of thunnosaur ichthyosaurs from the Middle Jurassic to the early Late Cretaceous worldwide. Almost all ichthyosaurs from the Middle Jurassic onwards belong to the family, until the extinction of ichthyosaurs in the early Late Cretaceous. Ophthalmosaurids appeared worldwide during early Bajocian, subsequent to the disappearance of most other ichthyosaur lineages after the end of the Toarcian. Currently, the oldest known ophthalmosaurids is Mollesaurus from the early Bajocian of Argentina, as well as indeterminate remains of the same age from Luxembourg and Canada. Named by George H. Baur, in 1887, the family contains the basal taxa like Ophthalmosaurus. Appleby (1956) named the taxon Ophthalmosauria which was followed by some authors, but these two names are often treated as synonyms; Ophthalmosauridae has the priority over Ophthalmosauria. However, some researchers argue that Ophthalmosauridae should be restricted to the group typically referred to as Ophthalmosaurinae, with classic Platypterygiinae instead being referred to as Undorosauridae or Brachypterygiidae and Ophthalmosauria being used to unite these two groups.

<i>Brachypterygius</i> Extinct genus of reptiles

Brachypterygius is an extinct genus of platypterygiine ophthalmosaurid ichthyosaur known from the Late Jurassic of England. The type species was originally described and named as Ichthyosaurus extremus by Boulenger in 1904. Brachypterygius was named by Huene in 1922 for the width and shortness of the forepaddle, and the type species is therefore Brachypterygius extremus. The holotype of B. extremus was originally thought to be from the Lias Group of Bath, United Kingdom, but other specimens suggest it more likely came from the Kimmeridgian Kimmeridge Clay of Kimmeridge Bay, Dorset, UK.

<i>Undorosaurus</i> Extinct genus of reptiles

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.

Mollesaurus is an extinct genus of large ophthalmosaurine ophthalmosaurid ichthyosaur known from northwestern Patagonia of Argentina.

<i>Nannopterygius</i> Extinct genus of reptiles

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<i>Chacaicosaurus</i> Extinct genus of reptiles

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<i>Grendelius</i> Extinct genus of reptiles

Grendelius is a genus of platypterygiine ophthalmosaurid ichthyosaur from the Late Jurassic (Kimmeridgian-Tithonian) of the UK and European Russia. It was a medium-sized ichthyosaur measuring about 4 metres (13 ft) long.

<i>Maiaspondylus</i> Extinct genus of reptiles

Maiaspondylus is an extinct genus of platypterygiine ophthalmosaurid ichthyosaurs known from Northwest Territories of Canada, the Cambridge Greensand of England and the Voronezh Region of Russia.

Simbirskiasaurus is an extinct genus of ichthyosaur from the Early Cretaceous of Ulyanovsk Oblast, Russia. Its type specimen is YKM 65119, a fragmentary skull and vertebral column.

<i>Arthropterygius</i> Extinct genus of reptiles

Arthropterygius is a widespread genus of ophthalmosaurid ichthyosaur which existed in Canada, Norway, Russia, and Argentina from the late Jurassic period and possibly to the earliest Cretaceous.

Sveltonectes is an extinct genus of platypterygiine ophthalmosaurid ichthyosaurs known from Ul’yanovsk region, western Russia.

<i>Acamptonectes</i> Extinct genus of ophthalmosaurid ichthyosaur known from England and Germany

Acamptonectes is a genus of ophthalmosaurid ichthyosaurs, a type of dolphin-like marine reptiles, that lived during the Early Cretaceous around 130 million years ago. The first specimen, a partial adult skeleton, was discovered in Speeton, England, in 1958, but was not formally described until 2012 by Valentin Fischer and colleagues. They also recognised a partial subadult skeleton belonging to the genus from Cremlingen, Germany, and specimens from other localities in England. The genus contains the single species Acamptonectes densus; the generic name means "rigid swimmer" and the specific name means "compact" or "tightly packed".

<i>Sisteronia</i> Extinct genus of reptiles

Sisteronia is an extinct genus of platypterygiine ophthalmosaurid ichthyosaur known from the 'middle' Cretaceous of southeastern England and southeastern France. It contains a single species, Sisteronia seeleyi.

<i>Pervushovisaurus</i> Extinct genus of reptiles

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<span class="mw-page-title-main">Timeline of ichthyosaur research</span>

This timeline of ichthyosaur research is a chronological listing of events in the history of paleontology focused on the ichthyosauromorphs, a group of secondarily aquatic marine reptiles whose later members superficially resembled dolphins, sharks, or swordfish. Scientists have documented ichthyosaur fossils at least as far back as the late 17th century. At that time, a scholar named Edward Lhuyd published a book on British fossils that misattributed some ichthyosaur vertebrae to actual fishes; their true nature was not recognized until the 19th century. In 1811, a boy named Joseph Anning discovered the first ichthyosaur fossils that would come to be scientifically recognized as such. His sister Mary would later find the rest of its skeleton and would go on to become a respected fossil collector and paleontologist in her own right.

Muiscasaurus is an extinct genus of ophthalmosaurid ichthyosaur that lived in modern Colombia during the Early Cretaceous. The only known species is the type Muiscasaurus catheti.

References

  1. Storrs, G. W.; Arkhangel'skii, M. S.; Efimov, V. M. (2000). "Mesozoic marine reptiles of Russia and other former Soviet republics". In Benton, M. J.; Shishkin, M. A.; Unwin, D. M.; Kurochkin, E. N. (eds.). The Age of Dinosaurs in Russia and Mongolia. Cambridge: Cambridge University Press. pp. 187–210.
  2. Maisch, M. W.; Matzke, A. T. (2000). "The Ichthyosauria". Stuttgarter Beiträge zur Naturkunde, Serie B. 298: 1–159.
  3. McGowan, C.; Motani, R. (2003). Sues, H.D. (ed.). Handbook of Paleoherpetology Part 8: Ichthyopterygia. Munich: Verlag Dr. Friedrich Pfeil. ISBN   3899370074.
  4. Fischer, V.; Bardet, N.; Benson, R. B. J.; Arkhangelsky, M. S.; Friedman, M. (2016). "Extinction of fish-shaped marine reptiles associated with reduced evolutionary rates and global environmental volatility". Nature Communications. 7: 10825. Bibcode:2016NatCo...710825F. doi:10.1038/ncomms10825. PMC   4786747 . PMID   26953824.
  5. Zverkov, N. G.; Efimov, V. M. (2019). "Revision of Undorosaurus, a mysterious Late Jurassic ichthyosaur of the Boreal Realm" (PDF). Journal of Systematic Palaeontology. 17 (14): 963–993. Bibcode:2019JSPal..17.1183Z. doi:10.1080/14772019.2018.1515793.
  6. Zverkov, N. G.; Jacobs, M. L. (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.