Saber-Toothed Cats: Big Jaw, Wimpy Bite

Oct. 2, 2007 — Despite their 7-inch canines, sharp claws and strong limbs, saber-toothed cats delivered a surprisingly wimpy bite, concludes a new study.

The cats, sometimes referred to as saber-toothed tigers, weighed around 450 pounds and were about the size of modern lions, but the study found a lion today could win a theoretical biting match with its prehistoric foe, Smilodon fatalis, which has been extinct for 10,000 years.

"Bite force driven by jaw muscles was relatively weak in S. fatalis, one-third that of a lion of comparable size, and its skull was poorly optimized to resist the extrinsic loadings generated by struggling prey," wrote the research team, which was led by Colin McHenry, a researcher in the School of Engineering and the School of Environmental and Life Sciences at the University of Newcastle.

The biting power of saber-toothed cats has been studied before, but McHenry and his colleagues suggest their new paper, published in this week's Proceedings of the National Academy of Sciences, provides the most detailed and accurate analysis.

The team combined computerized, 3-D reconstructions of the cat's jaw with models that simulate its bite in action.

When put under various kinds of stress, the recreated canines, jaw, and neck muscles showed varying degrees of weakness with color codes ranging from blue (low stress) to red (near collapse). The higher the researchers cranked up the load, the greater the pressure on the simulated skull, with most stress hitting the cat's lower jaw and gigantic upper teeth.

In contrast, the computer-modeled lion skull mostly stayed cool blue.

The findings are at first puzzling, given that saber-tooths are known to have caught and killed large animals, such as mammoths, bison and horses.

The researchers speculate the ancient cat, which first emerged around 3 million years ago, used "its massive size, robusticity and hypertrophied (excessively developed) dew claws" to "bring down large animals without biting until the prey was grounded." Once the cat had pinned down its victim, the scientists then think it directed a "killing bite" to the neck.