Phosphatosaurus

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
Phosphatosaurus
Temporal range: Early Eocene, 48.6 Ma (ghost lineage extends from Maastrichtian)[1]
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Crocodylomorpha
Family: Dyrosauridae
Genus: †Phosphatosaurus
Bergounioux, 1955
Species
  • <templatestyles src="Noitalic/styles.css"/>P. gavialoides Bergounioux, 1955 (type)

Lua error in Module:Taxonbar/candidate at line 22: attempt to index field 'wikibase' (a nil value).

Phosphatosaurus is an extinct genus of dyrosaurid crocodylomorph. It existed during the early Eocene, with fossils having been found from North Africa in Tunisia and Mali. Named in 1955, Phosphatosaurus is a monotypic genus; the type species is P. gavialoides.[2] A specimen has been discovered from Niger, but it cannot be classified at the species level.[3]

Phosphatosaurus is closely related to the Cretaceous genus Sokotosuchus, which is known from Niger and Mali. Because Phosphatosaurus is only known from Paleogene localities, the close relationship with Sokotosuchus implies that there is a long ghost lineage extending back into the Maastrichtian that is not known in the fossil record.[1]

Description

Phosphatosaurus is a large-bodied dyrosaurid with blunt teeth.[1][2][4] The tip of the snout is spoon-shaped from a lateral expansion of the rostral portion of the mandible. The dentition is nonhomodont. Alveolar "couplets" are present in the lower jaw of Phosphatosaurus in which paired tooth sockets, or alveoli, are closer to one another than to the alveoli next to them. This is not seen in any other dyrosaurid but is seen in some other longirostrine (long snouted) crocodylomorphs such as the gavialoid Eosuchus.[5] It is possible that the diastemata between the couplets served to receive larger maxillary teeth.[1]

Classification

Phosphatosaurus was assigned in 1979 to the newly named subfamily Phosphatosaurinae by Eric Buffetaut, who considered the subfamily to be the clade formed by Phosphatosaurus and the closely related Sokotosaurus.[6] However, other authors of more recent studies have been tentative in considering the taxon valid because there is currently little knowledge of the anatomy of either genus.[4]

Phylogenetics

Phylogenetic position of Phosphatosaurus
Buffetaut 1978[7]
Dyrosauridae 

Phosphatosaurus




Rhabdognathus




Hyposaurus



Dyrosaurus





Jouve 2005[8]
Dyrosauridae 

Sokotosuchus



Phosphatosaurus




Dyrosaurus




Hyposaurus



Rhabdognathus





Jouve et al. 2005[4]
Dyrosauridae 

Chenanisuchus





Sokotosuchus



Phosphatosaurus





Dyrosaurus




Arambourgisuchus



Congosaurus



Hyposaurus



Rhabdognathus






Phosphatosaurus is considered to be a basal dyrosaurid, and is often positioned near the base of phylogenetic trees of dyrosaurids. An early phylogenetic analysis by Buffetaut (1978), not based on a cladistic data matrix, puts Phosphatosaurus at the base of the tree due to the presence of many primitive characters in the genus.[7] Later phylogenetic analyses, such as the one by Jouve (2005), have also shown Phosphatosaurus to be a basal member of the family.[8] In most analyses, Phosphatosaurus and Sokotosuchus form a clade. These two genera are more closely related to one another than to any other genus of dyrosaurid. More recent phylogenetic studies have considered Chenanisuchus, a short-snouted dyrosairid named in 2005, to be even more basal than the clade containing Phosphatosaurus and Sokotosuchus.[9]

References

<templatestyles src="Reflist/styles.css" />

Cite error: Invalid <references> tag; parameter "group" is allowed only.

Use <references />, or <references group="..." />

External links

  1. 1.0 1.1 1.2 1.3 Lua error in package.lua at line 80: module 'strict' not found.
  2. 2.0 2.1 Lua error in package.lua at line 80: module 'strict' not found.
  3. Lua error in package.lua at line 80: module 'strict' not found.
  4. 4.0 4.1 4.2 Lua error in package.lua at line 80: module 'strict' not found.
  5. Lua error in package.lua at line 80: module 'strict' not found.
  6. Lua error in package.lua at line 80: module 'strict' not found.
  7. 7.0 7.1 Lua error in package.lua at line 80: module 'strict' not found.
  8. 8.0 8.1 Lua error in package.lua at line 80: module 'strict' not found.
  9. Lua error in package.lua at line 80: module 'strict' not found.