Dinosaurs generally had but one type of tooth, although the teeth of one dinosaur may be quite different from the next. Mammals, by contrast, have a variegated dentition including cutting, tearing and chewing teeth.
A dinosaur usually had longer hind limbs than forelimbs, reflecting its bipedal ancestry. Brachiosaurus, a close relative of our most common local dinosaur, is a noted exception.
Dinosaurs were basically land dwellers; they did not fly nor did they do a lot of swimming. Swamps were not popular with them, contrary to common belief.
As land dwellers, one of their most important features was a fully erect gait (see Figs. 5 and 8).
They did not sprawl, but walked with their legs straight under their bodies.
This fact is reflected in their hip joints, which were tight cylinder joints, and in their trackways, which were narrow___in some cases even pigeon-toed___with little sign of tail dragging.
They had high skulls and generally deep rib cages.
Many walked on two legs.
Some of the very large ones were four-legged; however, even the biggest may have been able to rear up on their hind legs when trying to reach high vegetation. There were many more plant-eaters than meat-eaters.
They generally laid hard-shelled eggs, but some may have borne live young.
