Nimravus (Greek for "ancestral hunter"); pronounced nim-RAY-vuss
Woodlands of North America
Oligocene-Early Miocene (30 to 20 million years ago)
Size and Weight:
About 4 feet long and 100 pounds
Short legs; dog-like feet
As you travel further and further back in time, it becomes increasingly difficult to separate the earliest felines from other predatory mammals. A good example is Nimravus, which was vaguely catlike in appearance with some hyena-like characteristics (the giveaway was this predator's single-chambered inner ear, which was much simpler than that of the true cats that succeeded it). Nimravus is considered to be the ancestor of the "false" saber-toothed cats, a line that includes Dinofelis and Eusmilus. It probably made its living by chasing small, quivering herbivores across the grassy woodlands of North America.