In prehistoric times , before the 10th millennium BC , the Upper Pleistocene Eurasian cave lion had occurred throughout much of Eurasia , including the Caucasus , what is now Siberia in Russia .
What used to be Beringia .
In prehistoric times , before the 10th millennium BC , the Upper Pleistocene Eurasian cave lion had occurred throughout much of Eurasia , including the Caucasus , what is now Siberia in Russia , and what used to be Beringia .