Whence the beardogs? Reappraisal of the Middle to Late Eocene “Miacis” from Texas, USA, and the origin of Amphicyonidae

CT and renewed scoring of TMM 40209-200 and the Angelarctocyon jaw sample support reassignment of two Texas “Miacis” species to distinct genera recovered as basal amphicyonids, but geographic origin and exact branching order remain model-dependent.

Expanded early-amphicyonid morphology sampling recovers Amphicyonidae as a basal caniform branch outside Canoidea, while exact sister relationships remain unresolved; the family is not a dog–bear ancestor blend or one linear lineage.

Angelarctocyon australis is bounded by holotype TMM 41850-1 and referred jaw material from the Chambers Tuff within an approximately 42–38 Ma sample envelope; this is not a global genus duration or direct ancestor interval.

Gustafsonia cognita is bounded by CT-reconstructed holotype cranium TMM 40209-200 from the Chambers Tuff within an approximately 38–36.6 Ma sample envelope; the interval is not a global family first appearance or direct ancestry date.

Amphicyonidae navigation display is displayed at 42–1.8 Ma only as the source-bounded family sample, not a continuous global range or direct dog–bear ancestry. The interval is a source-bounded sample window, not a global FAD, LAD, divergence date, continuous occupancy claim or direct-ancestor assertion.