Protocyon was a hypercarnivore, suggested by its dental adaptations. Like many other large canids, it was most likely a pack hunter. It hunted the medium-sized grazers and browsers, and bite marks on fossils suggest that it may have hunted Glyptotherium.[2] The find of a molar tooth found inSanta Vitória do PalmarinBrazil suggests a weight of between 25 and 37 kilograms (55 and 82 pounds) for this particular specimen.[3]: 219 , modest in size compared to other canids including the dire wolf. However, despite its size, isotopic analysis shows a dietary overlap with Smilodon populator, which implies it competed with the sabertooth cat for the same prey.[4]
Protocyon was named by Giebel in 1855 and assigned to Canidae by Carroll in 1988.[5]: 634 One taxonomic authority proposes that the species Theriodictis tarijensis falls under the genus Protocyon.[6]
A member of the Cerdocyonina lineage, its closest living relative might be the bush dog.
Canid fossil material from the Hoyo Negro pit in the Sac Actun cave system (Mexico), initially identified as remains of a coyote, was reinterpreted as remains of P. troglodytes by Schubert et al. (2019), indicating that this taxon was also present in the southern part of North America.[9]: 2
^Bocherens, Hervé; Cotte, Martin; Bonini, Ricardo; Scian, Daniel; Straccia, Pablo; Soibelzon, Leopoldo; Prevosti, Francisco J. (1 May 2016). "Paleobiology of sabretooth cat Smilodon populator in the Pampean Region (Buenos Aires Province, Argentina) around the Last Glacial Maximum: Insights from carbon and nitrogen stable isotopes in bone collagen". Palaeogeography, Palaeoclimatology, Palaeoecology. 449: 463–474. Bibcode:2016PPP...449..463B. doi:10.1016/j.palaeo.2016.02.017. hdl:11336/43965.