Saber Tooth

They've unearthed bones of a saber tooth tiger just north of Las Vegas. This creature is still a mind boggling creature that our not so distant forbearers had to battle whilst wandering the plains. The beast grew to about 15 feet in length (though one species was only the size of a bob-cat) and ranged upward to 900 lbs. Its not known whether they hunted in packs like lions, or were solitary predators, like the North American Mountain Lion. The size of their prey would indicate a pack-like approach.

Of course meeting even one would be enough.