As far as it goes we have andrewsarchus, sabertooth, dire wolf and bears, and Thylas, but never a species of bear dog so without further a due the amphicyon.
Wild: Upon crossing the savannah of scorched earth in search of water I stumbled across a morrelatops to rehydrate my canteens with a flash before my eyes an amphicyon pounced on this beast pinning it down with no struggle at all. This animal was the size of nearly a carno or even more possibly even being one of the like only apex mammalian apex predators on this ark it size may make look like it’s slow but beleive me I couldn’t even notice it at all.
Domesticated: My theory to tame this would be more likely be battling the beast in a duel of combat as this beast gives of a warrior like behavior as continuously observing Amphicyon it embraces a warrior or gladiator like behavior fighting off whatever threatens or comes in its way as I beleive beating it combat would likely earn the Mammals respect and would like be humble to you and the way it acts in it environment it would likely have a camouflage like ability blending well to its environment and somehow gain a more strength buff when engaged in combat and possibly buffing Allies and whatever is around it. If obtaining this mammal is successful then it would be a powerhouse in a warfare environment.