4.6" Brontothere Fossil Knee Bone Eocene Age Badlands S Dakota Titanothere COA

Location: White River Badlands, South Dakota

Weight: 1 Pound 0.8 Ounces

Dimensions: 4.6 Inches Long, 3.6 Inches Wide, 2.4 Inches Thick (Matrix)

Eocene Age, 56 to 33.9 million years Old.

Comes with a Certificate of Authenticity.

The item pictured is the one you will receive. 

Brontothere is an ancient mammal that roamed the area of Badlands National Park about 56-33.9 million years ago. Badlands brontotheres are also known as Megacerops coloradensis in scientific literature. Sometimes called “titanothere,” its name means “thunder beast,” referring to how a traveling herd of massive brontotheres may have sounded long ago, thundering through ancient environments.

Brontotheres from the Badlands would have reached impressive dimensions, standing around 8 feet tall and measuring up to 16 feet long, comparable in size to a modern large rhinoceros or small elephant. However, early Eocene brontotheres were only dog-sized. Over the course of 20 million years, they evolved and diversified, gradually increasing in size until they reached the massive proportions preserved in late Eocene Badlands fossils.

A defining characteristic of brontotheres is their paired blunt horns that extended from the nose. These horns developed from small nubs into enormous structures, sometimes exceeding 3.3 feet (1 meter) in length. Horn size generally varies by sex, with males typically sporting larger horns than females. While their appearance often brings modern rhinos to mind, brontotheres are only distant relatives. True rhino ancestors, such as Subhyracodon, also appear in the Badlands fossil record, representing the direct lineage of today’s rhinoceroses.