Ophthalmosauridae

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Ophthalmosaurids
Temporal range: Middle Jurassic-Late Cretaceous, 174.1–93.9  Ma
OphthalmosaurusIcenius-NaturalHistoryMuseum-August23-08.jpg
Composite skeleton (NHMUK PV R3702, R3893, R4124) of Ophthalmosaurus icenicus at the Natural History Museum, London
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Ichthyosauria
Clade: Baracromia
Family: Ophthalmosauridae
Baur, 1887
Subgroups
Synonyms
  • Ophthalmosauria

Ophthalmosauridae is an extinct family of thunnosaur ichthyosaurs from the Middle Jurassic to the early Late Cretaceous (Bajocian - Cenomanian) worldwide. [1] 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. [2] Currently, the oldest known ophthalmosaurids is Mollesaurus from the early Bajocian of Argentina, [3] as well as indeterminate remains of the same age from Luxembourg and Canada. [2] Named by George H. Baur, in 1887, the family contains the basal taxa like Ophthalmosaurus . [1] Appleby (1956) named the taxon Ophthalmosauria which was followed by some authors, [4] [5] but these two names are often treated as synonyms; Ophthalmosauridae has the priority over Ophthalmosauria. [1] 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. [6] [7]

Phylogeny

Life restoration of Ophthalmosaurus Ophthalmosaurus icenicus updated reconstruction.png
Life restoration of Ophthalmosaurus

Ophthalmosauridae is a node-based taxon defined by Ryosuke Motani (1999) as "the last common ancestor of Brachypterygius extremus and Ophthalmosaurus icenicus and all of its descendants". The definition he proposed for Ophthalmosauria was exactly the same. [4] In this case both definitions are synonyms. The cladogram below follows the topology from a 2010 analysis by Patrick S. Druckenmiller and Erin E. Maxwell. [5]

Thunnosauria  

Ichthyosaurus

Stenopterygius

"Ophthalmosaurus" natans (= Baptanodon )

 Ophthalmosauridae 

Valentin Fischer, Edwige Masure, Maxim S. Arkhangelsky and Pascal Godefroit (2011) described a new genus of Ophthalmosauridae. They redefined it as "the last common ancestor of Arthropterygius chrisorum and Ophthalmosaurus icenicus and all of its descendants". In this case Ophthalmosauria isn't a junior synonym of Ophthalmosauridae. The cladogram below follows Fischer et al. 2011. [1]

Thunnosauria  

*Note: Placement of Ophthalmosauria by definition.

Fischer et al. (2012) described another new genus of Ophthalmosauridae. They defined for the first time two subfamilies within the Ophthalmosauridae, Ophthalmosaurinae and Platypterygiinae. Ophthalmosaurus and Platypterygius were found to be non-monophyletic. Ophthalmosauridae was characterized by a reduced extracondylar area, a plate-like dorsal trochanter, a humerus with a facet for an anterior accessory element and the absence of notching on the paddle elements of the forefin. The cladogram below follows Fischer et al. 2012. [9]

Thunnosauria  

Since 2019

In 2019, two species of Cryopterygius were assigned to the genus Undorosaurus by Zverkov & Efimov (2019). 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. [10]

The following cladogram shows a possible phylogenetic positions within Ophthalmosauridae according to the analysis performed by Zverkov and Jacobs (2020). [11]

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.

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

<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.

<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

Nannopterygius is an extinct genus of ophthalmosaurid ichthyosaur that lived during the Middle Jurassic to the Early Cretaceous. Fossils are known from England, Kazakhstan, Russia, and Norway and six species are currently assigned to the genus.

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

Chacaicosaurus is a genus of neoichthyosaurian ichthyosaur known from the Middle Jurassic of Argentina. The single known specimen of this genus was excavated from the Los Molles Formation in Neuquén Province, and is housed at the Museo Olsacher under the specimen number MOZ 5803. This specimen consists of a skull, forelimb, some vertebrae, and some additional postcranial elements. The genus was named by Marta Fernández in 1994, and contains a single species, Chacaicosaurus cayi, making it the first named distinctive ichthyosaur from the Bajocian stage. It is a medium-sized ichthyosaur with a very long snout, which bears a ridge running along each side. The forelimbs of Chacaicosaurus are small and contain four main digits.

<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".

<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.

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

Ophthalmosaurinae is an extinct subfamily of ophthalmosaurid thunnosaur ichthyosaurs from the Middle Jurassic to the late Early Cretaceous of Europe, North America and South America. Currently, the oldest and the basalmost, known as ophthalmosaurine is Mollesaurus from the early Bajocian of Argentina. Ophthalmosaurines were characterized by a large extracondylar area of the basioccipital in the form of a thick and concave peripheral band, posterodistally deflected ulnar facet of the humerus, large ulna with concave and edgy posterior surface and ischiopubis with 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.

<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.

References

  1. 1 2 3 4 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. 1 2 Fischer, Valentin; Weis, Robert; Thuy, Ben (2021-02-22). "Refining the marine reptile turnover at the Early–Middle Jurassic transition". PeerJ. 9: e10647. doi: 10.7717/peerj.10647 . ISSN   2167-8359. PMC   7906043 . PMID   33665003.
  3. Marta S. Fernández (1999). "A new ichthyosaur from the Los Molles Formation (Early Bajocian), Neuquen Basin, Argentina". Journal of Paleontology. 73 (4): 677–681. doi:10.1017/S0022336000032492. JSTOR   1306766. S2CID   130751356.
  4. 1 2 Ryosuke Motani (1999). "Phylogeny of the Ichthyopterygia" (PDF). Journal of Vertebrate Paleontology. 19 (3): 472–495. doi:10.1080/02724634.1999.10011160. Archived from the original (PDF) on 2016-03-05. Retrieved 2011-10-19.
  5. 1 2 Patrick S. Druckenmiller; Erin E. Maxwell (2010). "A new Lower Cretaceous (lower Albian) ichthyosaur genus from the Clearwater Formation, Alberta, Canada". Canadian Journal of Earth Sciences. 47 (8): 1037–1053. Bibcode:2010CaJES..47.1037D. doi:10.1139/E10-028.[ permanent dead link ]
  6. Zverkov, N. G.; Efimov, V. M. (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.
  7. 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.
  8. 1 2 3 4 Arkhangel'sky, M. S., 1998, On the Ichthyosaurian Genus Platypterygius: Palaeontological Journal, v. 32, n. 6, p. 611-615.
  9. Valentin Fischer; Michael W. Maisch; Darren Naish; Ralf Kosma; Jeff Liston; Ulrich Joger; Fritz J. Krüger; Judith Pardo Pérez; Jessica Tainsh; Robert M. Appleby (2012). "New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary". PLOS ONE. 7 (1): e29234. Bibcode:2012PLoSO...729234F. doi: 10.1371/journal.pone.0029234 . PMC   3250416 . PMID   22235274.
  10. 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.
  11. Nikolay G. Zverkov & Megan L. Jacobs (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.