[D] Heterodontosaurus tucki [Su] [sG] [T]
Crompton & Charig, 1962
Jurassic Early Hettangian Sinemurian
Ornithischia Ornithopoda Heterodontosauridae
Upper Elliot Formation, Clarence Formation, Cape Province, South Africa
Genus - Typespecies - Skull
2 complete skulls, 1 associated with complete skeleton, fragmentary jaw.
This turkey- sized plant-eater was one of the earliest and smallest ornithopods (\\\\\\\"bird feet\\\\\\\")- dinosaurs with three long, forward-facing toes on each foot. The skeleton shows Heterodontosaurus\\\\\\\'s short, deep skull, curved neck, and fairly short back. Bony tendons stiffened the dorsal and sacral vertebrae but not the caudal vertebrae. Sturdy arms bore five- fingered, grasping hands. The legs were more than a third longer than the arms, and in the legs the tibia (shine bone) was nearly a third longer than the femur (thigh bone). each foot bore one short toe and three long, clawed ones. The skull featured a toothless beak, sharp canine-like teeth, close-packed cheek teeth with chisel-like crowns. Length 1.2m (4ft) Weight 2.5kg (5.5lb )
Heterodontosaurus was discovered by an expedition from Britain orginised by Dr. Alan Charig of the Britisch Museum (Natural History), and Dr. John Attridge and Dr. Barry Cox of the University of London. The head is quite similar in shape to that of Lesothosaurus but the teeth are notably different. At the front of the lower jaw is a familiar horn-covered predentary, and immediately behind this there is a very large tusk-like tooth-like the one seen in Lycorhinus- and then a row of chisel-edged cheek teeth.
The reconstructed skeleton of Heterodontosaurus shows it to be a lightly-built agile animal, typical of the early ornithopods. In particular the foot bones (metatarsals) and lower leg bones are elongated relative to the upper leg bone (femur). This kind of long, slender hind leg is a sure sign of a fleet-footed runner which presumably relied on speed to escape from its predators. The long tapering tail acted as a counterbalance for the front half of the body and was probably held out almost horizontaly above the ground when the animal ran. The large tusks are probably a male characteristic. It has been suggested that Abrictosaurus (the skull without tusks) may be a female, while Heterodontosaurus (with the tusks) is a male of the same species.
\\\\\\\"different-teeth lizard\\\\\\\" Many reptiles posses only one type of tooth. Heterodontosaurus had three kinds: sharp upper front teeth that bit against a toothless, horny neak; long canine tusks that fitted into groves in the top and bottum jaws; and high-crowned cheek teeth. | In recognition of the generous help afforded to the Expedition by Mr. G. C. Tuck, managing director of the Austin Motor Co. of South Africa (Proprietary) Ltd