After the nonavian dinosaurs became extinct, mammals became the dominant life forms. The first felinelike mammal, Proailurus, evolved about 30 million years ago. It is thought that all true cat species evolved from this small civetlike predator.
Cats that resemble today’s felids first appeared in the early Pliocene Epoch (5.3 to 3.6 million years ago), and they have continued into present times with remarkably few changes. The original design of fang and claw, flexible backbone, muscular strength, and agility allowed felids to survive and adapt to the changes brought by each new era. Adaptations have occurred with changes in prey, but the basic body type has stayed the same.