Assertion: bison's ancestor | /r/AtLocation | the fossil record
Facets:
value: during the oligocene in eurasia
type: TEMPORAL
Source sentences:
text: Members of the genus Cervus (and hence early relatives or possible ancestors of the elk) first appear in the fossil record 25 million years ago, during the Oligocene in Eurasia, but do not appear in the North American fossil record until the early Miocene.