Trilophosauridae

From Palaeos

Parent taxa:

(check the following menu and phylogeny - the taxon in bold refers to the topic on this page)

ARCHOSAUROMORPHA - Archosauromorpha, Archosauria (clade), Thecodontia (grade)
Taxonomy	Phylogeny
Subphylum: Vertebrata Class: Reptilia Subclass: Diapsida Infraclass: ARCHOSAUROMORPHA Order: Rhynchosauria Order: Trilophosauridae Order: Prolacertiformes Order: "Thecodontia" Order: Crocodylia Order: Pterosauria Superorder: Dinosauromorpha Order: ?Choristodera	o Sauria \|--Lepidosauromorpha `--o Archosauromorpha \|?--Choristodera `--+--Rhynchosauria `--+--Trilophosauridae `--+--Prolacertiformes `--o--Proterosuchidae `--+--Erythrosuchidae `--+--Euparkeriidae `--o--Proterochampsidae `--o Archosauria \|--o Ornithodira \| \|--Pterosauria \| `--Dinosauromorpha `--Crurotarsi
Archosauromorpha topics: \| Archosauromorpha Characteristics \| Ecology \| Evolutionary History \| Archosauriformes \| Archosauria \| "Thecodontia" \| References \| Links

Trilophosauridae

Trilophosaurus CC-by-2.5 Arthur Weasley

1 Introduction
2 Information
3 Characters
4 References
5 External links
6 Credits

[edit] Introduction

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, 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.

[edit] Information

Range: ?Early Triassic to Late Triassic of North America.

Phylogeny: Archosauromorpha ::: (Prolacertiformes + Archosauriformes) + Trilophosauridae.

Class: Reptilia
- Subclass: Diapsida
  - Infraclass: Archosauromorpha
    - Order: Trilophosauria
    - Author: Romer, 1956
      - Family: Trilophosauridae
      - Author: Gregory, 1945

[edit] Characters

The following section of this page needs to be wikified. At its simplest, wikifying can just mean adding links to other pages via the edit tab. For help in editing Palaeos org pages, see the edit help page

Characters: Similar to Rhynchosaurs, 2-3 m. Skull 10-15 cm long; dermal bones smooth; premaxilla and opposite surface of dentary without teeth, possibly with horn beak; snout very narrow; cheek teeth expanded transversely to sharp slicing surfaces; lower temporal fenestra and maxillary fenestra absent; orbits large, high on skull, and closely spaced on the narrow skull; orbits extensively floored by jugals and palatines; lacrimal small, not reaching nares; septomaxilla absent; skull highly consolidated, with sides tall and essentially vertical; dorsal surface of skull table dominated by large, wide fenestrae; high, narrow parietal crest between upper fenestrae; post-temporal bar narrow, overhanging occiput; quadrate tall with a marked posterior notch; tabulars, postparietals and supratemporals absent; wide, somewhat elongated ventral spines; heavy tail with long, heavy chevrons; no suggestion of upright carriage; phalanges very long; herbivorous

[edit] 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
Jalil, N-E (1997), A new prolacertiform diapsid from the Triassic of North Africa and the interrelationships of the Prolacertiformes. J. Vert. Paleontol. 17: 506-525
Parks, P (1969), "Cranial Anatomy and Mastication of the Triassic Reptile Trilophosaurus". M.A. thesis, U. Texas. 88 pp