Almasaurus

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Almasaurus
Temporal range: Late Triassic
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Almasaurus

Dutuit, 1972
Species
  • A. habbaziDutuit, 1972 (type)

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.

Contents

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]

Capitosauroidea

  Trematosauria  
unnamed

Aphaneramma

Trematolestes

unnamed

Lyrocephaliscus

Rileymillerus

unnamed

Almasaurus

unnamed

Metoposauridae

Callistomordax

See also

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<span class="mw-page-title-main">Eryopoidea</span> Extinct superfamily of amphibians

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<span class="mw-page-title-main">Trematosauria</span> Extinct clade of amphibians

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<i>Sclerocephalus</i> Extinct genus of amphibians

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<i>Lapillopsis</i> Extinct genus of amphibians

Lapillopsis is an extinct genus of stereospondyl temnospondyl within the family Lapillopsidae. Fossils belonging to the genus have been found in the Arcadia Formation of Queensland, Australia.

Rileymillerus is an extinct genus of temnospondyl amphibian from the Late Triassic Post Quarry in the Dockum Group of Texas that was described by John Bolt and Sankar Chatterjee in 2000. The holotype, a nearly complete skull with articulated jaws, is housed at the Museum of Texas Tech University. The genus is named for Riley Miller, who allowed Chatterjee to work on the Post Quarry, and the species is named for the paleontologist John Cosgriff.

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<span class="mw-page-title-main">Capitosauria</span> Extinct clade of amphibians

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<i>Callistomordax</i> Extinct genus of amphibians

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<span class="mw-page-title-main">Erfurt Formation</span>

The Erfurt Formation, also known as the Lower Keuper, is a stratigraphic formation of the Keuper group and the Germanic Trias supergroup. It was deposited during the Ladinian stage of the Triassic period. It lies above the Upper Muschelkalk and below the Middle Keuper.

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References

  1. 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.
  2. Wilson, J. A. (1948). "A small amphibian from the Triassic of Howard County, Texas". Journal of Paleontology. 22: 359–361.
  3. 1 2 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.
  4. 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.
  5. 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 .
  6. 1 2 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 .
  7. 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.