Early dog — Hesperocyon gregarius
Geologic period: Oligocene — Orellan
Age: Oligocene, Orellan.
Feeding: Carnivorous or omnivorous predatory mammal.
Evidence: Skull and jaw anatomy directly document early canid features.
Why it matters: Hesperocyon shows that the dog lineage had already begun diversifying tens of millions of years before wolves, coyotes and modern foxes appeared.
Plain Language Identity: An early member of the dog family lineage from the Oligocene.
What You Are Looking At: Hesperocyon fossil material representing an early canid.
Ecosystem: Oligocene terrestrial ecosystem of North America.
Source Urls: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list; https://www.si.edu/object/nmnhpaleobiology_3440634
Formation: Brule Formation, White River Group
Find Location: Wyoming, United States.
Enrichment Method: SAGE curated research pass; title + scientific name + source scene matched; chronology and taxonomy conflicts retained rather than silently corrected; evidence separated from inference
Scientific name: Hesperocyon gregarius
Evidence / representation: Representative evidence-type visual; not the exact specimen.
Representative evidence-type visual; not the exact specimen.
After the Dinosaurs: Mammals, Ice Ages and the World We Inherited.
This object page stays inside SAGE Museum. The Smithsonian link below is provided only as the original scholarly collection record. It opens separately.