Metoposaurus

Metoposaurus Temporal range: Carnian, 228–216.5 Ma PreЄ Є O S D C P T J K Pg N
Skeleton of Metoposaurus diagnosticus krasiejowensi in the Krasiejów museum in Poland
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Order:	†Temnospondyli
Suborder:	†Stereospondyli
Family:	†Metoposauridae
Genus:	†Metoposaurus Lydekker, 1890
Species
†M. diagnosticus (von Meyer, 1842) (type) †M. diagnosticus diagnosticus Fraas, 1889 †M. diagnosticus krasiejowensi Sulej, 2002 †M. diagnosticus algarvensis Brusatte et al 2015 †M. maleriensis Chowdhury, 1965 Nomina dubia: †M. azerouali Dutuit, 1976 †M. fraasi Lucas, 1904 †M. jonesi Case, 1920 †M. santaecruci Koken, 1913
Synonyms
Genus-level: Trigonosternum Schmidt, 1931 Species-level: M. heimi Kuhn, 1932 M. stuttgartiensis Fraas, 1913 Trigonosternum latum Schmidt, 1931

Nomina dubia:

Genus-level:

Species-level:

Metoposaurus (pronounced Me-top-o-sore-us) meaning "front lizard" is an extinct genus of Stereospondyli temnospondyl amphibian, known from the Late Triassic of Germany, Italy, Poland, and Portugal. This mostly aquatic animal possessed small, weak limbs, sharp teeth, and a large, flat head. This highly flattened creature mainly fed on fish, which it captured with its wide jaws lined with needle-like teeth. Metoposaurus was up to 3 m (10 feet) long and weighed 454 kg (1,000 pounds),. Many Metoposaurus mass graves have been found, probably from creatures that grouped together in drying pools during drought.

The lacrimal contacts the nasal medially, the maxilla laterally, the prefrontal posteromedially, and the jugal posteriorly. Metoposaur taxonomy was based on the position of lacrimal bone, and differing opinions have been published. According to photograph published by Hunt (1993), it is noted that the lacrimal enters the orbit contrary to previous finding by Fraas (1889). According to Lucas, close examination of the skull and other metoposaur skulls does not support this claim and it has been noted that the misidentification was possible due to the poor preservation of fossil. In 2007, Sulej noted that the variability in the position of lacrimal is narrow enough to be used for phylogeny analysis but with caution.

Study conducted by Sulej (2007) shows that the parietal contacts the frontal anteriorly, the postfrontal anterolaterally, the supratemporal laterally, and the postparietal posteriorly. The pineal foramen is in the posterior region of the parietal. An interesting feature pointed out by Sulej on examining the skull of Metoposaurus diagnosticus krasiejowensis is that it has a shorter prepineal region of the parietal than Metoposaurus diagnosticus diagnosticus and the expansion angle of the suture separating the parietal from the supratemporal has a lower value

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