8" Brontotherium Fossil Limb Bone Eocene Age White River Badlands SD Titanothere

Location: White River Badlands, South Dakota

Weight: 2 Pounds 8.6 Ounces

Dimensions: 8 Inches Long, 5 Inches Wide, 2.4 Inches Thick (Matrix)

The item pictured is the one you will receive.

This is a genuine fossil

Brontotheres were ancient mammals that roamed the area now known as Badlands National Park between approximately 38 and 34 million years ago. Scientifically known as Megacerops coloradensis, these prehistoric giants are sometimes called “titanotheres,” meaning “thunder beasts,” a name inspired by the imagined rumble of a herd of massive brontotheres moving through ancient landscapes.

Fossil evidence shows that Badlands brontotheres reached impressive sizes, standing around 8 feet tall and measuring up to 16 feet long, roughly the size of a modern large rhinoceros or small elephant. Despite their enormous size in the late Eocene, early Eocene brontotheres were only dog-sized. Over the course of 20 million years, they gradually evolved and diversified, growing larger and developing the distinctive physical traits that make the Badlands fossils so remarkable today.

One of the most striking features of brontotheres is their paired blunt horns that protrude from the nose. These horns grew from small nubs into massive structures, sometimes exceeding 3.3 feet (1 meter) in length, with males typically bearing larger horns than females. While these horns may evoke comparisons to modern rhinoceroses, brontotheres are only distantly related. The Badlands fossil record also contains species such as Subhyracodon, which are true ancestors of modern rhinoceroses, providing valuable insight into the evolutionary history of the rhino family and the diversity of prehistoric North American ecosystems.