Heterodontosaurus

Taxobox
name = "Heterodontosaurus"
fossil_range = Early Jurassic

---

image_caption = "Heterodontosaurus tucki"
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Ornithischia
familia = Heterodontosauridae
genus = "Heterodontosaurus"
genus_authority = Crompton & Charig, 1962
subdivision_ranks = Species
subdivision =
*"H. tucki" Crompton & Charig, 1962 (type)

"Heterodontosaurus" (meaning "different toothed lizard") is a genus of small herbivorous dinosaur with prominent canine teeth which lived in the Early Jurassic of South Africa. It was similar to a hypsilophodont in shape, and ate plants, despite its canines.

"Heterodontosaurus" is currently known from specimens of the SAFM (South African Museum) from South Africa. There are two known morphologies of this genus, the second of which is thought by some to represent a different species. The type species, "H. tucki", is from the Upper Elliot Formation of the Hettangian age, around 199-196 million years ago.

Description

"Heterodontosaurus" was a small, fleetfooted ornithischian that reached a maximum size of about 3 feet. It had a long, narrow pelvis and a pubis which resembled those possessed by more advanced ornithischians.

More unusual was that the hand of "Heterodontosaurus" had five fingers, two of which seem to be opposable. This configuration allowed "Heterodontosaurus" to grasp and manipulate food. The bone in the foot and ankle were fused in a manner reminiscent of those in birds.

Dentition

Another interesting feature is the specialization of teeth which gave rise to the animal's name. Most dinosaurs (and indeed most reptiles) have a single type of tooth in their jaws, while "Heterodontosaurus" had three. At the front of the jaw beside the beak were small teeth likely used for chopping off leaves and stems."Heterodontosaurus." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. "The Age of Dinosaurs". Publications International, LTD. p. 37. ISBN 0-7853-0443-6.]

Next in the jaw was a large pair of tusks whose purpose is unknown, but it is speculated that they were used as sexual displays. The final type of teeth were tall and squared off. This type of teeth was well adapted for chewing. Fleshy cheeks helped keep the food in the mouth while chewing occurred. Chewing is relatively common in dinosaurs, but uncommon for other groups of reptiles.

References

* "Dinosaurs and other prehistoric creatures". edited by Ingrid Cranfield, 2000. Salamander Books, pg 132-135.