They've evolved at least five times in mammals, most notably in the saber-tooth cat Smilodon, who sported serrated sabers that could measure nearly one foot long. But behind the fearsome ...

They've evolved at least five times in mammals, most notably in the saber-tooth cat Smilodon, who sported serrated sabers that could measure nearly one foot long. But behind the fearsome appearance of ...

from saber-toothed cats to panda bears. First, they estimated their strength using engineering computer models. RAYFIELD: So whereas you can do this for cars and bridges, you can also do it for teeth.