英語聽力：冰河綠洲—6

These holes are the unmistakable hallmark of a violent death. Their shape suggest they were made by the teeth of a big cat, but which one? Today there’s only one large cat in the region, the Florida panther. Though similar to the cougar at the western states, it's now much rarer. But it was around during the ice age, so could it have killed the glyptodont?

Although it could easily manage a deer, the Florida panther was probably too small to tackle such a giant. But it wasn't the only big cat around 13,000 years ago. There was also the mighty American lion, powerful enough to kill a glyptodont.

The scimitar-toothed cat, known to attack young mammonths, was also big and strong enough. And then there was the most infamous cat of all, the sabertooth. Like the scimitar, it saved itsawesome fangs for slashing soft flesh. It would have been unlikely to risk breaking them on bony armor. But the warm climate of ice age Florida made it a sanctuary for anotherkiller cat. Still South America's top predator, the jaguar is capable of takingprey much larger than itself. Weight for weight, it's probably the most powerful cat alive today.