Far from being cute kitties, sabre-toothed tigers were lethal hunters, roaming North and South American until around 10,000 years ago, searching for bisons, camels and other unfortunate animals. Today we know them for their super-sized teeth – they had exceptionally large canines for biting their prey. Now new research published in the journal PloS One suggested that there's more to these feline killing machines than their teeth.
Wallace63 @ wikimedia" alt="The head of a Smilodon" />This is work from Julie Meachen-Samuels and her team in the US, who've been looking at sabre-tooth fossils. They noticed that sabre-tooth tiger canine teeth are oval in cross-section, unlike modern cats, whose teeth are round. Having oval-shaped teeth makes them vulnerable to fracturing and breaking if the animals prey is wriggling – not a good thing for a hunting cat. This led the researchers to think that sabre-tooths may have killed their prey in a different way to modern cats, and not relied quite so much on their impressive teeth.
The researchers measured bones from the fore-limbs of sabre-tooth tigers, and compared them with 28 other cat species living today, from a tiny cat to a tiger. They found that the sabre-tooth limbs were much chunkier and stiffer than expected, with prominent muscle-attachment sites on the bones. This suggests that sabre-tooth tigers had exceptionally powerful and strong forelimbs, compared to today's cats.
The scientists think that sabre-tooth tigers may have used their muscular forelimbs to immobilise their prey, before biting into them. This would have protected their vulnerable teeth, and built up their arms even more. Today's cats have stronger teeth, and weaker forelimbs, so they probably rely more on their teeth for hunting than their ancestors.