Bear dog

Amphicyon ingens, in the American Museum of Natural History in New York.

• North America
• Europe
• Asia
• Africa

The Amphicyonidae are an extinct family of dog -like predators. They originated in the Eocene, about 45 million years ago and survived until the late Miocene. The animals were like a mixture of bears and large dogs, whence the name derives bear dogs. People used to be unsure whether they are more likely attributable to the dogs or the bear, today they are mostly regarded as a separate family.

Most Amphicyoniden were robust animals with relatively short legs. Some like Cynelos were also built slimmer. Amphicyoniden were among the first representatives of the larger predators. An early species from the Eocene of Europe was Simamphicyon. During the Miocene, they produced many different forms, from omnivorous generalists to highly specialized predators. The most common genus was Amphicyon, the males of which could reach up to 300 kg body weight. The powerful fangs of this genus were probably likely to bite through large bones. This assumption is also supported by large muscle attachment sites at their skull.

The Amphicyonidae first appeared in the Eocene of North America about 45 million years ago. In the late Eocene, about 35 million years ago, they had spread to Europe. Asia and Africa they reached in the early Miocene epoch, about 23 million years ago. The last members of the family died out about 8 million years ago in the late Miocene.