Bison (Bison antiquus)
Bison in North America migrated from Eurasia in waves via the Bering corridor.
Ancestors of modern bison apparently arrived here during the last interglacial
episode (Sangamon). The earliest ancestor, represented by Bison antiquus,
was up to one third larger than modern representatives and persisted as
late as 10,000 years ago. Meanwhile they had spread over most of America,
south of the Wisconsin Episode ice. Bison antiquus lived in herds
with habits like those of modern bison. That they were hunted by paleo-Indians
is demonstrated by numerous kill sites, some containing remains of some
200 individuals. Distinquished by their large size, long horns and a large
hump, they apparently were displaced by modern bison, which expanded in
great numbers over the western plains and as far east as Illinois.