Almasaurus
Almasaurus is an extinct genus of trematosaurian temnospondyl within the family Latiscopidae. It is known from several skulls and some postcranial material found from the Argana Formation in Morocco, which dates back to the Late Triassic. When it was first named in 1972, Almasaurus was placed within its own superfamily, the Almasauroidea. Although the related latiscopid Latiscopus disjunctus possesses exoccipitals that are underplated (a feature that suggests that it is a member of the family Trematosauridae) Almasaurus is not considered to be a trematosaurid because it lacks such underplating. Almasaurus was considered to be a capitosaurian by Warren & Black (1985) because it shared several characters with the group, including a deeply notched squamosal and a lacrimal flexure, while supposedly exhibiting none of the characters associated with trematosaurians. However, more recent studies have concluded that Almasaurus is either a temnospondyl more basal than the clade formed from the dichotomy between Capitosauria and Trematosauria or that the genus is closely related to the trematosaurian family Metoposauridae, perhaps being a sister taxon of it. A temnospondyl genus described in 2000, Rileymillerus, is thought to be closely related to Almasaurus. Below is a cladogram showing the phylogenetic position of Almasaurus, from Schoch (2008):
| Almasaurus Temporal range:
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|---|---|
Scientific classification 
| |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Tetrapoda |
| Order: | †Temnospondyli |
| Suborder: | †Stereospondyli |
| Family: | †Latiscopidae |
| Genus: | †Almasaurus Dutuit, 1972 |
| Type species | |
| †A. habbazi Dutuit, 1972
| |
Almasaurus is an extinct genus of trematosaurian temnospondyl within the family Latiscopidae. It is known from several skulls and some postcranial material found from the Argana Formation in Morocco, which dates back to the Late Triassic.
When it was first named in 1972, Almasaurus was placed within its own superfamily, the Almasauroidea.[1] Although the related latiscopid Latiscopus disjunctus possesses exoccipitals that are underplated (a feature that suggests that it is a member of the family Trematosauridae)[2] Almasaurus is not considered to be a trematosaurid because it lacks such underplating.[3] Almasaurus was considered to be a capitosaurian by Warren & Black (1985) because it shared several characters with the group, including a deeply notched squamosal and a lacrimal flexure, while supposedly exhibiting none of the characters associated with trematosaurians.[3] However, more recent studies have concluded that Almasaurus is either a temnospondyl more basal than the clade formed from the dichotomy between Capitosauria and Trematosauria[4] or that the genus is closely related to the trematosaurian family Metoposauridae, perhaps being a sister taxon of it.[5][6]
A temnospondyl genus described in 2000, Rileymillerus, is thought to be closely related to Almasaurus.[7]
Below is a cladogram showing the phylogenetic position of Almasaurus, from Schoch (2008):[6]
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See also
[edit]References
[edit]- ^ Dutuit, J.-M. (1972). "Un nouveau genre de Stégocephale du Trias Supérieur Marocain: Almasaurus habbazi". Bulletin du Museum national d'histoire naturelle, Paris. 3: 73–77.
- ^ Wilson, J. A. (1948). "A small amphibian from the Triassic of Howard County, Texas". Journal of Paleontology. 22: 359–361.
- ^ a b Warren, A.; Black, T. (1985). "A new rhytidosteid (Amphibia, Labyrinthodontia) from the Early Triassic Arcadia Formation of Queensland, Australia, and the relationships of Triassic temnospondyls". Journal of Vertebrate Paleontology. 5 (4): 303–327. doi:10.1080/02724634.1985.10011868.
- ^ Steyer, J. S. (2002). "The first articulated trematosaur 'amphibian' from the Lower Triassic of Madagascar: implications for the phylogeny of the group". Palaeontology. 45: 771–793. doi:10.1111/1475-4983.00260.
- ^ Yates, A. M.; Warren, A. A. (2000). "The phylogeny of the 'higher' temnospondyls (Vertebrata: Choanata) and its implications for the monophyly and origins of the Stereospondyli". Zoological Journal of the Linnean Society. 128: 77–121. doi:10.1111/j.1096-3642.2000.tb00650.x.
- ^ a b Schoch, R. R. (2008). "A new stereospondyl from the German Middle Triassic, and the origin of the Metoposauridae". Zoological Journal of the Linnean Society. 152: 79–113. doi:10.1111/j.1096-3642.2007.00363.x.
- ^ Bolt, J. R.; Chatterjee, S. (2000). "A new temnospondyl amphibian from the Late Triassic of Texas". Journal of Paleontology. 74: 670–683. doi:10.1666/0022-3360(2000)074<0670:ANTAFT>2.0.CO;2.
External links
[edit]- Almasaurus in the Paleobiology Database
