Those characteristics probably came in handy in ancient Alaska, where the wolves faced stiff competition for food from some very formidable competitors, she added, including lions, short-faced bears, and saber-tooth cats. During periods of intense competition among predators, modern-day wolves will also consume carcasses more fully, ingesting more bone and eating faster, which increases the risk of tooth fracture.

The long-ago demise of this specialized wolf form may portend things to come for specialized groups of existing predators, Van Valkenburgh said. For example, a unique type of nomadic North American gray wolf was recently discovered. Their packs migrate across the North American tundra along with caribou and keep their numbers in check. In contrast, all other wolves are territorial and non-migratory. Global warming threatens to eliminate the tundra and it is likely that this will mean the extinction of this important predator, she said.