Bison

The Bison (Bison bison) is a bovid mammal or a species of wild cattle. It appeared in a cameo at the beginning of the last episode of Walking with Beasts, where it was introduced as one of the representative species of the Ice Age (or mammoth) fauna. In reality, bison live only in the New World (North America), and so the animal featured there was actually the wisent (Bison bonasus), European cousin of the bison and its closest living relative and Old World (Eurasia) counterpart.

Walking With Beasts
The bison was one of the mammals that were a part of the so-called 'Mammth Fauna'. Consequently, in the last episode of "Walking with Beasts" a herd of bison was shown grazing alongside several woolly mammoths.