Double-horned rhinoceros — Menoceras arikarense
Geologic period: Oligocene — early Arikareean
Age: Oligocene in the Smithsonian catalog.
Feeding: Herbivorous.
Evidence: Skeletons and skulls directly preserve rhinoceros anatomy. Behavior associated with the paired nasal horn structures remains inferred.
Why it matters: Menoceras shows that rhinoceroses were once far more diverse in size and skull form than the surviving species suggest.
Plain Language Identity: A relatively small early rhinoceros from the Oligocene of North America.
What You Are Looking At: A composite reconstruction of Menoceras arikarense.
Ecosystem: Oligocene terrestrial plains 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_3342409
Formation: Harrison Formation, Arikaree Group
Find Location: Nebraska, 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: Menoceras arikarense
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.