Named By: Loomis - 1936.
Classification: Chordata, Mammalia, Carnivora, Caniformia, Amphicyonidae, Temnocyoninae.pe).
Species: M. obtusidens (type).
Size: Estimated around 39 kilograms in weight.
Known locations: USA.
Time period: Rupelian of the Oligocene through to the Aquitanian of the Miocene.
Fossil representation: Several specimens.
Mammacyon was a ‘bear dog’ that has been assigned to the Temnocyoninae, and not surprisingly is thought to have been considered to be similar to the group type genus Temnocyon. Mammacyon seems to have been active at the same time as Temnocyon as well as many of the same locations, although the current range of fossil deposits for Mammacyon suggests that it did not have the same broad distribution as Temnocyon. So far Mammacyon has only been found in Florida (south east USA) as well as Wyoming, Nebraska and South Dakota (central north USA). It’s quite reasonable that Mammacyon was also active between these areas at some point, but so far a lack of remains means that the full range of Mammacyon can only be speculated.