Litopterna (from Ancient Greek: λῑτή πτέρνα "smooth heel") is an extinct order of fossil hoofed mammals (ungulates) from the Cenozoic period that displayed toe reduction - three-toed forms developed; there was even a one-toed horse-like form.
The Litopterns probably became stranded in South America after it broke away from the rest of the world during the end of the Eocene, 35 MYA. The Litopterns survived there in isolation for most of the Cenozoic, but when during the Pliocene South America connected with North America, starting the Great Faunal Interchange, the Litopterns began to decline, and by 20 000 years ago, during the Pleistocene, they all died out.
In Walking with... SeriesEdit
Macrauchenia was one of the main characters of this episode. It is also the only Litoptern to feature in any IP production up to date. It was a fast, wary animal, which was preyed upon by Terror Birds and Smilodon, and which lived in groups to escape predators.