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Oreodont brain casts

Bowl of Oreodont brain casts

Bathygenys reevesi
TMM 40209 – multiple specimens
Found in the Reeves Bonebed, Presidio County, Texas
Lived about 36 million years ago

This bowl is filled with casts, or natural copies of the brain, from extinct mammals called Oreodonts. Think of it as a bowl of brains! After the animals died, sand and mud filled the empty skulls and hardened into these fossils. Since soft brain tissue is never preserved in a fossil, these casts give scientists important clues about what the brain was like. The brain lobes and creases can be seen on the darker brown casts.

Oreodonts were small hoofed mammals that are most-closely related to present-day camels and llamas. These fossils are part of over 100 brain casts that were found at the Reeves Bonebed northwest of Presidio, Texas. Scientists have found so many skulls and broken limb bones in the Reeves Bonebed that they believe it was the home of a carnivore that preyed on oreodonts.