Badlands National Park
Today, after a heavy rainstorm in the Badlands, vivid red bands stand out against the buff tones of the buttes. Geologists and paleontologists tell us these are fossilized soils, which make up much of the Badlands rocks. Fossil soils can tell us a great deal about the climatic history of the Badlands; they also impart much of the colorful banding to Badlands rocks. Perhaps the best of all, the loose, crumbling rocks formed from these ancient soils hold one of the greatest collections of fossil mammals on Earth.
The White River Badlands of South Dakota are considered to be the birthplace of the science of vertebrate paleontology. The park has a full-time professional paleontologist, as well as an active agreement with the South Dakota School of Mines for fossil preparation. Although some visitors are disappointed when they learn that Badlands National Park is not home to dinosaurs, the rich diversity of extinct mammal life becomes fascinating. Ancestors of the modern day rhinoceros, horse, pig, cat, and many other species are present. There are also early birds, reptiles, and invertebrates found in various strata.
An array of extinct animals, ranging from very enormous to very small, once ranged through the area now included in Badlands National Park. Within the park, the fossilized remains of a variety of animals have been found. Baculites, an extinct cephalopod, had a squid-like body with a long cylindrical shell tightly coiled at one end. Inside the shell were individual chambers containing either gas or liquid for buoyancy control. Clams, crabs, and snails in great numbers have also been found. Outside the park, the Pierre shale has yielded abundant remains of ancient fish; mosasaurs, giant marine lizards; pterosaurs, flying reptiles; Archelon, enormous sea turtles; and Hesperonis, a diving bird something like a modern loon.
Other species lived in the subtropical forests that flourished after the retreat of the shallow inland seas, while others inhabited the savannahs and grasslands that came in the years afterward. Some of these creatures, whose fossils have been found in the Badlands, probably lived in the geologic epoch known as the Oligocene, that lasted from 23 to 35 million years ago. This period is also known as "the Age of Mammals."
An interesting array of mammal fossils have been found. Leptomeryx, small, fragile, and deer-like, had even-toed hooves and browsed on the stems and leaves of early Oligocene vegetation. Oreodonts, sheep-like in appearance, were extremely abundant. Their name means "mountain tooth." Archaeotherium, a distant relative of modern pigs, had sharp canines and fed on both plants and carrion. An ancestor of modern horses, mesohippus, had three toes instead of the one hoof. Hoplophoneus, one of the earliest of the mammals to be called a saber-tooth cat, was about the size of a leopard. An agile rhinoceros, subhyracodon was a plant-eater. Ischromys, a small squirrel-like rodent probably lived in trees and ate a diet of fruits and nuts. Metamynodon was a massive rhinoceros that, like the hippopotamus, spent much of its time in the water. Paleolagus, perhaps an ancestral rabbit, nibbled on plants.
Details mentioned in this article were accurate at the time of publication