英语听力：冰河绿洲—7

But most significant of all, the jaguar has a tell-tale trademark. Instead of going for the neck or snout like most cats do, it kills with a crushing bite through the skull into the brain. This makes the jaguar prime suspect in this case. Even the glyptodont's defences had a fatal flaw.

13,000 years ago, another very different kind of hunter reached this warm corner of the continent. Florida's springs have produced an unparalleled record of these first people, examples of theircraftsmanship and hunting expertise, including razor-sharp flint spear points.

The area was rich in flint for making weapons and in animals to hunt. And with the milder climate, these people probably had an easier life than their contemporaries further north. Small clues to their arrival have survived undamaged over 13,000 years—spear points, fishhooks and other glimpses of their daily life showing the versatility of these first inhabitants of the Sunshine State.

They hunted a wide range of ice age animals and Florida possesses a unique record of one such encounter. The skull of an extinct bison restored here was discovered in one of the rivers. Planted deep in the top of the skull was a flint spear point.