Thalattosuchia

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Thalattosuchians
Temporal range: Sinemurian - Early Aptian 190–125 Ma
Platysuchus multiscrobiculatus 1.JPG
Platysuchus,(Teleosauridae, Teleosauroidea)
Geosaurus fossil.JPG
Cricosaurus (Metriorhynchidae, Metriorhynchoidea)
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Pseudosuchia
Superorder: Crocodylomorpha
Clade: Solidocrania
Suborder: Thalattosuchia
Fraas, 1901[1]
Superfamilies
Life restoration of Metriorhynchus brevirostris (Metriorhynchidae)

Thalattosuchia are a clade of marine crocodylomorphs from the Early Jurassic to the Early Cretaceous that had a cosmopolitan distribution.[3] They are colloquially referred to as marine crocodiles or sea crocodiles, though they are not members of Crocodilia. The clade contains two major subgroupings, the Teleosauroidea and Metriorhynchoidea. Teleosauroids are not greatly specialised for oceanic life, with back osteoderms similar to other crocodyliformes. Within Metriorhynchoidea, the Metriorhynchidae displayed extreme adaptions for life in the open ocean, including the transformation of limbs into flippers, the development of a tail fluke, and smooth, scaleless skin.[4]

The oldest records of thalattosuchians date to the Sinemurian and Pliensbachian stages, represented by indeterminate remains from Argentina, Chile, and India.[5] Thalattosuchians are abundant during the Jurassic, but are rare during the Early Cretaceous.[6]

The term Thalattosuchia was coined by Fraas in 1901.[1] Various authors considered Thalattosuchia an infraorder or a suborder within "Mesosuchia". However, the term "Mesosuchia" is a paraphyletic group, and as such is no longer used. For consistency, the Thalattosuchia are here placed at suborder rank, although the order that contains it is unnamed. The exact phylogenetic position of Thalattosuchia is uncertain, with them either being interpreted as members of Neosuchia or basal members of Crocodylomorpha, with the similarities to neosuchians possibly being due to convergence.[7]

Since Buffetaut (1982) demonstrated the shared characteristics of the early forms of Metriorhynchidae and Teleosauridae, Thalattosuchia has consisted of these two families.[8]

Some of the early members of Teleosauridae have been discovered in non-marine deposits. The systematics of the genus Pelagosaurus are confused, with differencing topologies placing it as either a teleosaurid,[9] or as the sister taxon to a Teleosauridae + Metriorhynchoidea clade. Others considered Pelagosaurus to be a basal metriorhynchoid.[8]

See also[edit]

References[edit]

  1. ^ a b Fraas E. 1901. Die Meerkrokodile (Thalattosuchia n. g.) eine neue Sauriergruppe der Juraformation. Jahreshefte des Vereins für vaterländische Naturkunde, Württemberg 57: 409-418.
  2. ^ Fitzinger LJFJ. 1843. Systema Reptilium. Wien: Braumüller et Seidel, 106 pp.
  3. ^ Alfio A. Chiarenza, Davide Foffa, Mark T. Young, Gianni Insacco, Andrea Cau, Giorgio Carnevale, Rita Catanzariti (2015). "The youngest record of metriorhynchid crocodylomorphs, with implications for the extinction of Thalattosuchia". Cretaceous Research. 56: 608–616. doi:10.1016/j.cretres.2015.07.001.{{cite journal}}: CS1 maint: uses authors parameter (link)
  4. ^ Spindler, Frederik; Lauer, René; Tischlinger, Helmut; Mäuser, Matthias (2021-07-05). "The integument of pelagic crocodylomorphs (Thalattosuchia: Metriorhynchidae)". Palaeontologia Electronica. 24 (2): 1–41. doi:10.26879/1099. ISSN 1094-8074.
  5. ^ Bardet, N.; Falconnet, J.; Fischer, V.; Houssaye, A.; Jouve, S.; Pereda Suberbiola, X.; Pérez-García, A.; Rage, J.-C.; Vincent, P. (November 2014). "Mesozoic marine reptile palaeobiogeography in response to drifting plates". Gondwana Research. 26 (3–4): 869–887. Bibcode:2014GondR..26..869B. doi:10.1016/j.gr.2014.05.005. ISSN 1342-937X.
  6. ^ Young, Mark T.; Sachs, Sven (2021-09-02). "Evidence of thalattosuchian crocodylomorphs in the Portland Stone Formation (Late Jurassic) of England, and a discussion on Cretaceous teleosauroids". Historical Biology. 33 (9): 1473–1476. doi:10.1080/08912963.2019.1709453. ISSN 0891-2963. S2CID 213426116.
  7. ^ Wilberg, Eric W. (2015-07-01). "What's in an Outgroup? The Impact of Outgroup Choice on the Phylogenetic Position of Thalattosuchia (Crocodylomorpha) and the Origin of Crocodyliformes". Systematic Biology. 64 (4): 621–637. doi:10.1093/sysbio/syv020. ISSN 1076-836X. PMID 25840332.
  8. ^ a b Buffetaut, E. 1982. Radiation évolutive, paléoécologie et biogéographie des Crocodiliens mésosuchienes. Mémoires Societé Geologique de France 142: 1–88.
  9. ^ Gasparini Z, Pol D, Spalletti LA. 2006. An unusual marine crocodyliform from the Jurassic-Cretaceous boundary of Patagonia. Science 311: 70-73.

Further reading[edit]

  • Fraas, E. (1902). "Die Meer-Krocodilier (Thalattosuchia) des oberen Jura unter specieller Berücksichtigung von Dacosaurus und Geosaurus". Paleontographica 49: 1-72.

External links[edit]