I'm writing today to correct an error in my own books and to note how a mystery about the brown bear (Ursus arctos) has been with us for 72 years now.
In 1936, Swedish zoologist Sten Bergman published in the Journal of Mammology his notes on the bears of Kamchatka. In addition to his observations of living bears, he was shown the skin of a colossal, short-furred, solid black bear. He wrote that local hunters told him the very largest bears always looked like this. He recounted how another scientist had photographed an exceptionally large bear skull from the same region and described a pawprint 25cm across (18cm is a very large bear).
Several writers on the topic, myself included, have said Sten Bergman (not, incidentally, to be confused with Christian Bergmann, author of Bergmann's Rule), proposed the name Ursus piscator, later realigned as Ursus arctos piscator by other authorities, to describe a possible new species or subspecies of these huge, black, short-furred bears.
Looking now at the source material, I find that's not so. Bergman wrote of the possibility these bears were a separate species or subspecies from the brown bear, but he referred in his article only to an already-established scientific name, Ursus piscator (first used in 1865) used for all Kamchatkan brown bears.
Some sources still use U. a. piscator for Kamchatkan brown bears in general, although brown bear taxonomy remains inconsistent. So the lesson there is always to look at original sources (thanks to the two people who wrote me on how to get the 1936 article) and not just repeat another secondary source, even a respected source.
The mystery of Bergman's bear remains unsolved to this day.