Planocephalosaurus
| Planocephalosaurus Temporal range: Late Triassic | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Sauropsida |
| Order: | Sphenodontia |
| Family: | Sphenodontidae |
| Genus: | Planocephalosaurus Fraser, 1982[1] |
| Species | |
| |
Planocephalosaurus is an extinct genus of rhynchocephalian.
Planocephalosaurus was one of the first sphenodonts and bore a strong resemblance to the extant tuatara, albeit much smaller, at only 20 centimetres (7.9 in) in length. The creature is presumed to have fed on large invertebrates and small vertebrates.[2]
Dentition
"Planocephalosaurus" exhibits very interesting dentition. Initially, it was believed to have been attached to the bone via acrodont tooth implantation, however, after this specimen was exposed to X-radiography it was determined that this animal has a combination of different tooth implantation types.[1][3] Similar to another rhynchocephalian, Diphydontosaurus, it possesses acrodont teeth in the posterior portion of the jaw, and pleurodont dentition in the anterior portion.[3] Planocephalosaurus's teeth were also fused with the cartilage, unlike its only extant relative the tuatara.[2]
References
- 1 2 Fraser, N.C. (1982). "A New Rhynchocephalian from the British Upper Trias". Palaeontology. 25 (4): 709–725.
- 1 2 Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 85. ISBN 1-84028-152-9.
- 1 2 Fraser, N.C.; Shelton, C.G. (1988). "Studies of tooth impantation in fossil tetrapods using high-resolution X-radiography". Geologic Magazine. 125: 117–122.