Named By: Richard Lydekker - 1890.
Synonyms: Metopias, Metoposaurus heimi, Metoposaurus stuttgartiensis, Trigonosternum
Classification: Chordata, Amphibia, Temnospondyli, Stereospondyli, Metoposauridae.
Species: M. diagnosticus diagnosticus (type), 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.
Size: Up to 3 meters long.
Known locations: Across Europe including France - Gres à Avicula contorta Formation (Lorraine), Germany - Löwenstein Formation, Stuttgart Formation, Weser Formation (Baden-Württemberg 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.
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
Bogdania, Dutuitosaurus and Koskinonodon.
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.
- 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.