Platypterygius

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Platypterygius
Temporal range: Late Aptian-Late Cenomanian
113–93.9  Ma
Platypterygius australis.jpg
Assigned P. australis specimen
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Ichthyosauria
Family: Ophthalmosauridae
Subfamily: Platypterygiinae
Genus: Platypterygius
von Huene, 1922
Type species
Ichthyosaurus platydactylus
Broilli 1907
Other species
  • P. americanus
    (Nace, 1939)
  • P. australis
    (McCoy, 1867)
  • P. hercynicus
    Kuhn, 1946

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. [1] While fossils referred to Platypterygius have been found throughout different continents, the holotype specimen was found in Germany.

Contents

Description

Restoration of P. australis Platypterigius longmani DB.jpg
Restoration of P. australis

As Platypterygius contains multiple species not especially close to each other, little can be said in terms of shared characteristics. According to an analysis by Fischer (2012), all anatomical features used to unify Platypterygius species are either not actually present in each species, or much more widespread among unrelated ophthalmosaurs. Generally, species referred to this genus were large bodied macropredators based on their robust dentition. [2] This is also supported by P. australis having been found with remains of sea turtles and birds (specifically, of the genus Nanantius ) in its guts, [3] as well as an unidentified pterosaur fossil with tooth marks that may be from this genus.

In 1998, Arkhangelsky estimated that P. platydactylus was about 5 metres (16 ft) long, while "P." americanus was about 5.5 metres (18 ft) long. [4] In 2010, Zammit and colleagues estimated that "P." australis was about 7 metres (23 ft) long. [5]

Discovery and species

Skull of P. sp., Sternberg Museum of Natural History Platypterygius sp. (fossil Ichthyosaur).jpg
Skull of P. sp., Sternberg Museum of Natural History

The type species of Platypterygius was described in 1922 based on remains found in upper Aptian strata around Hannover, Germany. These remains however were not adequately described and to complicate matters further, destroyed during World War 2. In the time after its discovery however Platypterygius has become a catch-all genus for Cretaceous ichthyosaurs, creating the misconstrued view of post-Jurassic ichthyosaurs as being a single global genus lacking in diversity. Later research conducted in the 2000s and 2010s has repeatedly shown this to be false, with all of the autapomorphies previously used to define Platypterygius either not being present in all assigned species or also being present in other ophthalmosaurids. [6] As the holotype was destroyed, a redescription of the material attempting to identify valid autapomorphies is out of the question and leaves the genus in a problematic state. Furthermore, the inclusion of later described genera of Cretaceous, platypterygiine ichthyosaurs has shown Platypterygius to be paraphyletic, with the different species not clading closely to one another. Subsequently, many redescriptions of referred Platypterygius species have found them to be their own distinct genera.

One notable attempt at revising Platypterygius was conducted by Arkhangel'sky in 1998, who split the genus into 3 new subgenera. Longirostria (including the Australian "P." longmani, a synonym of "P." australis, and the Argentinian "P." hauthali), Tenuirostria ("P." americanus) and Pervushovisaurus (which included the newly described "P." bannovkensis). Both Platypterygius platydactylus,"P." kiprianoffi and "P." hercynicus were placed in the subgenus Platypterygius. [4]

"Platypterygius" bannovkensis was eventually elevated to its own genus Pervushovisaurus in 2014, utilizing Arkhangel'sky's proposed subgenus name [7] and "P." campylodon was also assigned to this genus by a study published in 2016. [8] "P." kiprianoffi was also assigned to P. campylodon (now Pervushovisaurus). [9] [10] [11] Simbirskiasaurus was originally described in 1985 and later sunk into Platypterygius before being declared distinct in the same paper as Pervushovisaurus. [7] "Platypterygius" ochevi, described in 2008 by Arkhangel'sky et al., was found to be a junior synonym of Maiaspondylus cantabrigiensis [12] and in 2021 "Platypterygius" sachicarum was described by Cortés et al. as Kyhytysuka sachicarum . [13] It is argued that the inclusion of oldest species "P." hauthali requires reinvestigation, [11] for it lacks a skull to attribute. [14] Because of this, recent analyses on ichthyosaur classification neglect this species. [15] [16] In 2024, "P." hauthali was reclassified back into the original genus, Myobradypterygius . [17]

Accepted species

Opalized vertebral column assigned to an immature P. cf. longmani (a synonym of P. australis) Opalised Ichthyosaur backbone.jpg
Opalized vertebral column assigned to an immature P. cf. longmani (a synonym of P. australis)

Formerly assigned species

Classification

Skeleton in Museum and Art Gallery of the Northern Territory Ichthyosaur Skeleton, Platypterygius longmani, in The Museum and Art Gallery of the Northern Territory at Darwin.jpg
Skeleton in Museum and Art Gallery of the Northern Territory

The following cladogram shows the internal relationships of ophthalmosaurian ichthyosaurs according to an analysis performed by Zverkov and Jacobs (2020) which shows that P. americanus is too distantly related compared to the other three species. [16]

Ophthalmosauria
Ophthalmosaurinae

Acamptonectes densus

Mollesaurus periallus

Ophthalmosaurus natans

Ophthalmosaurus icenicus

Gengasaurus nicosiai

Nannopterygius yasykovi

Nannopterygius enthekiodon

Nannopterygius saveljeviensis

Nannopterygius borealis

Arthropterygius volgensis

Arthropterygius lundi

Arthropterygius thalassonotus

Arthropterygius hoybergeti

Arthropterygius chrisorum

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

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 930–950 kg (2,050–2,090 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.

<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. Opthalmosaurids 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>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.

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

Athabascasaurus is an extinct genus of platypterygiine ophthalmosaurid ichthyosaur known from Alberta, Canada.

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".

<span class="mw-page-title-main">Platypterygiinae</span> Extinct subfamily of reptiles

Platypterygiinae is an extinct subfamily of ophthalmosaurid thunnosaur ichthyosaurs from the early Late Jurassic to the early Late Cretaceous of Asia, Australia, Europe, North America and South America. Currently, the oldest known platypterygiine is Brachypterygius. Platypterygiines were characterized by square tooth roots in cross-section, an extremely reduced extracondylar area of the basioccipital, prominent dorsal and ventral trochanters on humerus and ischiopubis lacking an obturator foramen.

<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

Pervushovisaurus is a genus of platypterygiine ichthyosaur from the Late Cretaceous (Cenomanian) of the Saratov region in western Russia, the La Penthiève Beds of France and the Cambridge area of the UK.

<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.

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

Keilhauia is a genus of ophthalmosaurid ichthyosaur, a type of dolphin-like, large-eyed marine reptile, from the Early Cretaceous shallow marine Slottsmøya Member of the Agardhfjellet Formation in Svalbard, Norway. The genus contains a single species, K. nui, known from a single specimen discovered in 2010 and described by Delsett et al. in 2017. In life, Keilhauia probably measured approximately 4 metres (13 ft) in length; it can be distinguished by other ophthalmosaurids by the wide top end of its ilium and the relatively short ischiopubis compared to the femur. Although it was placed in a basal position within the Ophthalmosauridae by phylogenetic analysis, this placement is probably incorrect.

Myobradypterygius is an extinct genus of ophthalmosaurid ichthyosaur from the Early Cretaceous (Barremian-Hauterivian) of Argentina and possibly also Chile. One species is known, M. hauthali, which was once believed to have been a species of Platypterygius.

References

  1. Fischer, V.; Masure, E.; Arkhangelsky, M.S.; Godefroit, P. (2011). "A New Barremian (Early Cretaceous) Ichthyosaur From Western Russia". Journal of Vertebrate Paleontology. 31 (5): 1010–1025. doi:10.1080/02724634.2011.595464. hdl: 2268/92828 . S2CID   86036325.
  2. 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.
  3. Kear, Benjamin P.; Boles, Walter E.; Smith, Elizabeth T. (2003). "Unusual gut contents in a Cretaceous ichthyosaur". Proceedings of the Royal Society B. 270 (Suppl 2): S206–S208. doi:10.1098/rsbl.2003.0050. PMC   1809966 . PMID   14667384.
  4. 1 2 Arkhangelsky, M.S. (1998). "On the Ichthyosaurian genus Platypterygius". Paleontological Journal . 32 (6): 611–615.
  5. Maria Zammit, Rachel M. Norris & Benjamin P. Kear (2010). "The Australian Cretaceous ichthyosaur Platypterygius australis: a description and review of postcranial remains". Journal of Vertebrate Paleontology. 30 (6): 1726–1735. doi:10.1080/02724634.2010.521930. S2CID   85089080.
  6. Fischer, V. (2012). "New Data on the Ichthyosaur Platypterygius hercynicus and Its Implications for the Validity of the Genus". Acta Palaeontologica Polonica. 57 (1): 123–134. doi: 10.4202/app.2011.0007 . S2CID   53355007.
  7. 1 2 Fischer, Valentin; Arkhangelsky, Maxim S.; Naish, Darren; Stenshin, Ilya M.; Uspensky, Gleb N.; Godefroit, Pascal (2014). "Simbirskiasaurus and Pervushovisaurus reassessed: implications for the taxonomy and cranial osteology of Cretaceous platypterygiine ichthyosaurs". Zoological Journal of the Linnean Society. 171 (4): 822–841. doi: 10.1111/zoj.12158 .
  8. 1 2 Fischer, V. (2016). "Taxonomy of Platypterygius campylodon and the diversity of the last ichthyosaurs". PeerJ . 4: e2604. doi: 10.7717/peerj.2604 . PMC   5075704 . PMID   27781178.
  9. "Mesozoic marine reptiles of Russia and other former Soviet Republics". The Age of Dinosaurs in Russia and Mongolia. Cambridge, UK: Cambridge University Press. 2000. pp. 187–210.
  10. McGowan, C.; Motani, R. (2003). "Ichthyopterygia". Handbook of Paleoherpetology. Munich, Germany. 8: 175.
  11. 1 2 Zammit, M. (2012). "Cretaceous Ichthyosaurs: Dwindling Diversity, or the Empire Strikes Back?". Geosciences. 2 (2): 187–210. Bibcode:2012Geosc...2...11Z. doi: 10.3390/geosciences2020011 .
  12. Nikolay G. Zverkov; Dmitry V. Grigoriev (2020). "An unrevealed lineage of platypterygiines (Ichthyosauria) with peculiar forefin structure and semiglobal distribution in the mid-Cretaceous (Albian–Cenomanian)". Cretaceous Research. 115: Article 104550. doi:10.1016/j.cretres.2020.104550. S2CID   225721312.
  13. Cortés, D.; Maxwell, E.E.; Larsson, H.C.E. (2021). "Re-appearance of hypercarnivore ichthyosaurs in the Cretaceous with differentiated dentition revision of Platypterygius sachicarum (Reptilia:Ichthyosauria, Ophthalmosauridae) from Colombia". Journal of Systematic Palaeontology. 19 (14): 969–1002. doi:10.1080/14772019.2021.1989507. S2CID   244512087.
  14. Maxwell, E.E.; Kear, B.P. (2010). "Postcranial anatomy of Platypterygius americanus (Reptilia: Ichthyosauria) from the Cretaceous of Wyoming". Journal of Vertebrate Paleontology. 30 (4): 1059–1068. doi:10.1080/02724634.2010.483546. S2CID   85817541.
  15. Nikolay G. Zverkov & Vladimir M. Efimov (2019). "Revision of Undorosaurus, a mysterious Late Jurassic ichthyosaur of the Boreal Realm". Journal of Systematic Palaeontology. 17 (14): 963–993. doi:10.1080/14772019.2018.1515793. S2CID   91912834.
  16. 1 2 Nikolay G. Zverkov; Megan L. Jacobs (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: 228–275. doi:10.1093/zoolinnean/zlaa028.
  17. Campos, L.; Fernández, M. S.; Bosio, V.; Herrera, Y.; Manzo, A. (2024). "Revalidation of Myobradypterygius hauthali Huene, 1927 and the phylogenetic signal within the ophthalmosaurid (Ichthyosauria) forefins". Cretaceous Research. 105818. doi:10.1016/j.cretres.2023.105818.
  18. 1 2 Fischer, Valentin; Arkhangelsky, Maxim S.; Naish, Darren; Stenshin, Ilya M.; Uspensky, Gleb N.; Godefroit, Pascal (2014). "Simbirskiasaurus and Pervushovisaurus reassessed: implications for the taxonomy and cranial osteology of Cretaceous platypterygiine ichthyosaurs". Zoological Journal of the Linnean Society . 171 (4): 822–841. doi: 10.1111/zoj.12158 .
  19. Páramo, M.E. (1997). "Platypterygius sachicarum (Reptilia, Ichthyosauria) nueva especie del Cretácico de Colombia". Revista INGEOMINAS. 6: 1–12.

Bibliography

Further reading