Battle of the big catsDr. Nicolas R. Chimento By Michael MarshallSabre-toothed cats may have used their fearsome canine teeth to bite their rivals in the head, puncturing their skulls and probably killing them. This seems to be the best explanation for two separate sabre-toothed cat skulls sporting tooth-shaped holes. The long-toothed cats roamed the world for over 40 million years before the last ones vanished 11,000 years ago. Although the canine teeth are dramatic, some palaeontologists think they were largely for show. They are so long and narrow, the argument goes, they must have been fragile and would …