Amphicyon
Amphicyon ("ambiguous dog") is an extinct genus of large carnivorous bone-crushing mammals, popularly known as bear-dogs, of the family Amphicyonidae, subfamily Amphicyoninae, from the Aquitanian Epoch until the early Pleistocene. They ranged over North America, Europe, Asia, and Africa from 20.6—1.8 Ma ago, existing approximately 18.8 million years.
Morphology
Amphicyon was the typical bear-dog amphicyonid with morphology similar to both bears and dogs. With its robust build and maximum length of 2.5 m (8 ft), the largest species looked more like a bear than a dog. It had a large heavy tail, thick neck, robust limbs and teeth like a wolf. It was probably an omnivore with a lifestyle comparable to that of the brown bear.
Body mass
A single specimen was examined by Legendre and Roth and estimated to have a body mass of 84.2 kg (190 lb), roughly half that of Ischyrocyon and twice that of Epicyon which shared its time period and habitat.
A. ingens was much bigger: Sorkin (2008) estimated the largest known specimen (AM 68108) to weigh 600 kg,<ref name = ""Sorkin">Sorkin, B. (2008-04-10). "A biomechanical constraint on body mass in terrestrial mammalian predators". Lethaia 41 (4): 333–347. doi:10.1111/j.1502-3931.2007.00091.x. Retrieved 2011-08-02. </ref> making it one of the largest known amphicyonids.