Fossil in the cave bear (Ursus spelaeus), a relative on the brown bear and polar bear within the Pleistocene epoch in Europe The subfamily Ursinae knowledgeable a remarkable proliferation of taxa about 5.3–4.5 Mya, coincident with major environmental improvements; the primary members from the genus Ursus appeared around this time. https://www.youtube.com/channel/UCCoZfLHRsYsRsVHqS-CSAWA