In fact teeth are highly molded by natural selection for efficiency in killing, shearing and chewing. The appearance of teeth alone reveals an animal's diet. Reptilian teeth were and are homodont . In carnivores efficient canine for piercing and carnasials for sheering flesh. In herbivores there is a good grinding surface.
Insectivores have very high interlocking cusps for crunching insects.
Better root system to hold teeth in precise place. Gives more fore-aft muscle orientation and thus greater mechanical efficiency. Bony processes at the hip , the elbow and ankle joints improved mechanical efficiency of muscles that rotated the limbs backward at these joints. 6. ribs were lost from cervical vertebrae and lumbar vertebrae - gave greater flexibility. Watch a cheetah run.