Fossil in the cave bear (Ursus spelaeus), a relative in the brown bear and polar bear from your Pleistocene epoch in Europe The subfamily Ursinae experienced a remarkable proliferation of taxa about five.three–4.5 Mya, coincident with main environmental improvements; the initial associates in the genus Ursus appeared about this time. https://www.youtube.com/channel/UCCoZfLHRsYsRsVHqS-CSAWA