Rarest bear

The world's rarest bear is a very controversial species referred to variously as the patriarchal bear, MacFarlane's bear, or the unexpected bear, and known only from a single specimen – a very large yellow-furred individual killed on 24 June 1864 by two hunters in Canada's Barren Ground region. It was originally assumed to be merely a grizzly bear, and its skull and pelt were given to amateur naturalist Roderick MacFarlane, who in turn donated them to the U.S. National Museum. When they were examined and formally documented in 1918 by renowned American naturalist Prof. C. Hart Merriam, however, he considered this bear to be so different from all previously documented forms that he officially classified it as a new bear species, which he named Vetularctos inopinatus, thus housing it in a new genus too. In recent times, conversely, other researchers have suggested that it is either just an unusual grizzly bear specimen or possibly a hybrid of grizzly bear and polar bear.

Hybrids of grizzly bears and polar bears are known as pizzlies, and several confirmed specimens have been recorded, mostly in captivity. In 2006, however, DNA tests conducted upon an unusual-looking bear that had been shot close to Sachs Harbour in the Canadian Arctic revealed it to be a pizzly, the first naturally occurring, wild-bred specimen ever verified.