Ursus maritimus tyrannus

Ursus maritimus tyrannus is an extinct subspecies of bear, known from a single fragmentary ulna found in the gravels of the Thames at Kew Bridge, London. It was named by the Finnish paleontologist Björn Kurtén in 1964 and is interpreted to represent a relatively large subadult individual, the ulna is estimated to have been 48.5 cm (19 in) long when complete.[1] Dating back to the Late Pleistocene, approximately 70,000 years ago, it is one of the oldest fossils assigned to the polar bear,[2] however, recent reinvestigation of the fossil suggest brown bear affinities instead.