proterothere

fossil mammal

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July 13, 2026

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Proterotheres were extinct hoofed mammals that lived in South America from the Paleocene Epoch (beginning about 65.5 million years ago) until the Pliocene Epoch (5.3 to 2.6 million years ago). They are part of the order Litopterna, which evolved in ways that paralleled hoofed mammals in the Northern Hemisphere.1

Proterotheres strongly resembled horses, with limbs adapted for running and knee-locking mechanisms for prolonged standing. Their skulls were long and low, featuring cheek teeth similar to those of deer. They became extinct around the time true horses first appeared in South America.1

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litoptern
One line of litopterns, the proterotheres, strongly resembled horses. Their limbs were modified for running and also had special features for locking their knees, allowing them to stand for long periods of time. The proterothere skull was long and low and contained cheek teeth resembling those of deer. Proterotheres became…
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One line of litopterns, the proterotheres, strongly resembled horses. Their limbs were modified for running and also had special features for locking their knees, allowing them to stand for long periods of time. The proterothere skull was long and low and contained cheek teeth resembling those of deer. Proterotheres became…
Read More