An Ancient Waterhole

Nineteen million years ago, this was a waterhole in the midst of a wide, shallow river valley where sparse vegetation, occasional clouds of volcanic dust, and extreme drought conditions prevailed. The waterhole was the lifeblood for animals from miles around as herds of large mammals called chalicotheres and ancient rhinoceroses converged here for water and devoured the remaining vegetation. As food became scarce, the weakened animals lay down in the cool waterhole to die, while beardogs and omnivorous entelodonts waited there to feed on the carcasses of the chalicotheres and rhinoceroses.

Nebraska · United States