Amphicyon (Greek for "ambiguous dog"); pronounced am-fih-SIGH-on
Plains of the northern hemisphere
Middle Oligocene-Early Miocene (30-20 million years ago)
Size and Weight:
About 6 feet long and 200 pounds
Large size; bear-like body
Despite its nickname, the "Bear Dog," Amphicyon was directly ancestral to neither bears nor dogs. This was the most prominent genus of the family of mammalian, vaguely canine-like carnivores that succeeded the larger "creodonts" (typified by Hyaenodon and Sarkastodon) but preceded the first true dogs. True to its nickname, Amphicyon looked like a small bear with the head of a dog, and it probably pursued a bear-like lifestyle as well, feeding opportunistically on meat, carrion, fish, fruit and plants. The front legs of this prehistoric mammal were especially well-muscled, meaning it could probably stun prey senseless with a single well-aimed swipe of its paw.