As a predator, having long, saberlike fangs is an advantage only if you can keep struggling prey from snapping them in half. A new study of fossils suggests that at least three different groups of ancient hunters solved that problem the same way. They evolved sturdy forelimbs that helped them hold prey firm during the kill. And the longer the teeth were, the burlier the bones.
Modern-day cats have fangs, but these teeth are relatively short and have a circular cross section—a profile that enables them to withstand stresses applied from any direction. But several extinct varieties of saber-tooth cats, including the famed Smilodon, whose fossils are found in large numbers in California’s La Brea Tar Pits, sported fearsome fangs that had either oval or bladelike cross sections. Teeth with those profiles are much more susceptible to breakage, especially if the thrashing of prey imposes side-to-side forces on the fangs, says Julie Meachen-Samuels, a paleobiologist at the National Evolutionary Synthesis Center in Durham, North Carolina.
Other groups of predatory mammals evolved saberlike teeth as well, including the Nimravidae, also known as false saber-tooth cats, which roamed Eurasia and North America between 42 million and 7 million years ago, and the so-called Barbourofelidae, which lived in Africa, Eurasia, and North America between 20 million and 5 million years ago. The skulls and physiques of these predators were remarkably similar, and the creatures occupied comparable ecological niches, Meachen-Samuels says. Although Nimravidae and Barbourofelidae had a somewhat different posture than modern cats and were slightly more flat-footed, she notes, “if you saw one of these animals from a distance, you’d think it was a cat…”