Name Meaning:  Large Horn Face
Alternate Names:  Brontops, Brontotherium, Menodus, Ateleodon, Titanotherium, Oreinotherium, Titanops
Geologic Era:  Eocene to Oligocene
Range:  Canada and Northern North America
Location Found:  South Dakota
Size: About 2.5 meters tall at shoulder, 4 meters long
Extinction Date:  30 million years ago

Our Megacerops specimen is very impressive in an of itself, but becomes even more so when one realizes that it is just the very top of a femur.  A human femur head is less than one fifth the circumference of Megacerops’.  I suspect that our specimen is from an older collection that was dismantled, as collecting is now illegal in that area.

Megacerops was an herbivore that bore something of a resemblance to the modern rhinoceros.  It was easily the largest known animal in its ecosystem, and is thought to have been a browser of leaves.  The world that Megacerops lived in was a lush, forested environment, not unlike a cool rainforest.  Even the largest predators of the time were in no way close to Megacerops in size, so it could be safe to assume that an adult, healthy Megacerops had little fear of predators.  Only young or weak animals would have to worry, though young Megacerops likely stayed close to their mothers, who would have been a very effective predator deterrent.  The only animal that could be a danger to a Megacerops would be another Megacerops.  One skeleton of a presumed male shows healed rib fractures that could be the result of intraspecific competition.  

Native Americans would occasionally find skeletons of Megacerops in the Black Hills region, particularly after a heavy rainstorm.  For this reason, the Sioux tribes called these animals “thunder horses,” since it was thought that these animals made rainstorms by running across clouds.  The animals that the Sioux uncovered were killed in probable volcanic eruptions from the nearby rocky mountains (as they tended to be found in groups).  One of the older names for Megacerops (Brontotherium) means “thunder beast.”

Megacerops and its kin were victims of a changing climate.  Toward the end of the Oligocene, the forests that Megacerops depended on started to give way to grasslands.  Megacerops was not as well equipped to survive on this type of food, and drifted toward extinction.  Other animals, such as primitive horses and deer, succeeded Megacerops and the dominant herbivores. 

Image Credits:
Skeleton:  By Osborn. – http://www.copyrightexpired.com/earlyimage/bones/display_osborn_brontotherium.htm, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4496079


Life Restoration:  By Creator:Dmitry Bogdanov – dmitrchel@mail.ru, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=9682585