Trilophosaur

Taxobox
name = Trilophosaurs
fossil_range = Triassic

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image_width = 250px
image_caption = restoration of "Trilophosaurus"
regnum = Animalia
phylum = Chordata
classis = Sauropsida
subclassis = Diapsida
infraclassis = Archosauromorpha
ordo = Trilophosauria
ordo_authority = Romer, 1956
familia = Trilophosauridae
familia_authority = Gregory, 1945
subdivision_ranks = Genera
subdivision = "Trilophosaurus"
"Tricuspisaurus"
"Variodens"

Trilophosaurs were lizard-like Triassic diapsid reptiles related to the archosaurs. The best known genus is "Trilophosaurus", a herbivore up to 2.5 meters long. It had a short, unusually heavily-built skull, equipped with massive, broad flattened cheek teeth with sharp shearing surfaces for cutting up tough plant material. Teeth are absent from the premaxilla and front of the lower jaw, which in life were probably equipped with a horny beak.

The skull is also unusual in that the lower temporal opening is missing, giving the appearance of a euryapsid skull, and originally the Trilophosaurs were classified with placodonts and sauropterygia. Carroll 1988 suggests that the lower opening may have been lost to strengthen the skull.

Trilophosaurs are so far known only from the Late Triassic of North America and Europe.

References

* Benton, M. J. (2000), "Vertebrate Paleontology", 2nd ed. Blackwell Science Ltd, p.144
* Carroll, R. L. (1988), "Vertebrate Paleontology and Evolution", W.H. Freeman & Co. p.266

External links

* [http://www.palaeos.com/Vertebrates/Units/270Archosauromorpha/270.200.html Archosauromorpha: Rhynchosaurs and "Trilophosaurus"] at Palaeos