Metoposaurus

Name: Metoposaurus ‭(‬Front lizard‭)‬.
Phonetic: Me-top-o-sore-us.
Named By: Richard Lydekker‭ ‬-‭ ‬1890.
Synonyms: Metopias,‭ ‬Metoposaurus heimi,‭ ‬Metoposaurus stuttgartiensis, Trigonosternum
Classification: Chordata,‭ ‬Amphibia,‭ ‬Temnospondyli,‭ ‬Stereospondyli,‭ ‬Metoposauridae.
Species: M.‭ ‬diagnosticus diagnosticus‭ (‬type‭)‬,‭ ‬M. algarvensis, M.‭ ‬diagnosticus krasiejowensi,‭ ‬M.‭ ‬maleriensis, M.‭ ‬ultimus.‭ ‬The additional species M.‭ ‬azerouali,‭ ‬M.‭ ‬fraasi,‭ ‬M.‭ ‬jonesi and M.‭ ‬santaecruci are sometimes mentioned,‭ ‬thought these are not considered valid by all.
Diet: Carnivore/Picivore.
Size: Up to‭ ‬3‭ ‬meters long.
Known locations: Across Europe including France‭ ‬-‭ ‬Gres � Avicula contorta Formation‭ (‬Lorraine‭)‬,‭ ‬Germany‭ ‬-‭ ‬L�wenstein Formation,‭ ‬Stuttgart Formation,‭ ‬Weser Formation‭ (‬Baden-W�rttemberg and Bayern for Stuttgart Formation‭)‬,‭ ‬Hassberge Formation‭ (‬Bayern‭)‬,‭ ‬Trossingen Formation‭ (‬Sachsen-Anhalt‭)‬,‭ ‬Italy‭ ‬-‭ ‬Raibl Beds Formation‭ (‬Bolzano‭) ‬and Poland‭ ‬-‭ ‬Drawno Beds Formation‭ (‬Opole‭)‬,‭ ‬as well as Canada‭ ‬-‭ ‬Wolfville Formation‭ (‬Nova Scotia‭)‬,‭ ‬USA‭ ‬-‭ ‬Santa Rosa Sandstone Formation and Dockum Formation‭ (‬both Texas‭)‬.‭ ‬Possibly also India‭ ‬-‭ ‬Tiki Formation‭ (‬Madhya Pradesh‭)‬.
Time period: Carnian to Rhaetian of the Triassic.
Fossil representation: Remains of multiple individuals.




       The genus Metoposaurus was originally named as Metopias by Christian von Meyer in‭ ‬1842,‭ ‬but the name was replaced and changed to Metoposaurus by Richard Lydekker in‭ ‬1890.‭ ‬Metoposaurus is the type species of the Metoposauridae,‭ ‬a group of temnospondyl amphibians that are particularly noted for having eyes that are placed further forward on the head.‭ ‬Relatives of Metoposaurus include Apachesaurus,‭ ‬Bogdania,‭ ‬Dutuitosaurus and Anaschisma.
       Like relative genera,‭ ‬Metoposaurus lived during the closing stages of the Triassic,‭ ‬and shows developments that best support a primarily if not an entirely aquatic lifestyle.‭ ‬Most obvious is the limb reduction,‭ ‬with the legs seemingly not large of strong enough to lift the body clear off the ground if an individual Metoposaurus found itself out of the water.‭ ‬The shape of the skull is also quite flat on top which means that a Metoposaurus near the surface of the water would not expose itself that much to anything that was on the surface.‭ ‬Grooves in the skull also hint at the presence of a sensory system similar to the lateral line of a fish which would have detected changes in water pressure caused by the movement of nearby animals.‭ ‬The latter development is not unique to the metoposaurid however since similar adaptations can also be seen on other genera such as Mastodonsaurus,‭ ‬though again this genus is widely believed to have been entirely aquatic.‭ ‬Another piece of evidence that supports an entirely aquatic lifestyle is the discovery of several Metoposaurus clustered together in what is thought to have been a dried out body of water,‭ ‬an occurrence which has also been seen in other related genera.

Further reading
- Species discrimination of the Late Triassic temnospondyl amphibian Metoposaurus diagnosticus. - Acta Palaeontologica Polonica. 47: 535–546. - T. Sulej - 2002.
- Osteology, variability, and evolution of Metoposaurus, a temnospondyl from the Late Triassic of Poland. - Palaeontologica Polonica. 64: 29–139. - T. Sulej - 2007.
-‭ ‬A new metoposaurid‭ (‬temnospondyl‭) ‬bonebed from the Late Triassic of Portugal‭ ‬-‭ ‬J.‭ ‬S.‭ ‬Steyer,‭ ‬O.‭ ‬Mateus,‭ ‬R.‭ ‬J.‭ ‬Butler,‭ ‬S.‭ ‬L.‭ ‬Brusatte‭ & ‬J.‭ ‬H.‭ ‬Whiteside‭ ‬-‭ ‬2011.
Unique growth pattern of Metoposaurus diagnosticus krasiejowensis (Amphibia, Temnospondyli) from the Upper Triassic of Krasiej�w, Poland. - Palaeogeography, Palaeoclimatology, Palaeoecology 370 (2013): 145-157. - Dorota Konietzko-Meier & Nicole Klein - 2013.
- A new species of Metoposaurus from the Late Triassic of Portugal and comments on the systematics and biogeography of metoposaurid temnospondyls. - Journal of Vertebrate Paleontology. 35: e912988. - S. L. Brusatte, R. J. Butler, O. Mateus & S. J. Steyer - 2015.
- Ornamentation of dermal bones of Metoposaurus krasiejowensis and its ecological implications. - PeerJ. 6: e5267. - M. Antczak & A. Bodzioch - 2018.
- Redescription of Arganasaurus (Metoposaurus) azerouali (Dutuit) comb. nov. from the Upper Triassic of the Argana Basin (Morocco), and the first phylogenetic analysis of the Metoposauridae (Amphibia, Temnospondyli). - Papers in Palaeontology. - Valentin Buffa, Nour-Eddine Jalil & J.Sebastien Steyer - 2019.



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