Taxonomy
- Kingdom: Animalia
- Phylum: Chordata
- Class: Mammalia
- Order: Notoungulata
- Suborder: Toxodontia
- Family: Notohippidae
- Genus: Notohippus
Geological age
- Middle to Late Miocene (approximately 13–5 million years ago).
Geographic distribution
- Fossils have been recovered primarily from Argentine Patagonia, notably the Santa Cruz and Collón Curá formations.
Morphology
- Medium‑sized notoungulate with a body plan superficially similar to that of modern horses.
- Dentition includes high‑crowned (hypsodont) cheek teeth adapted for grazing on abrasive vegetation.
- Limb bones indicate a cursorial (running) lifestyle, with elongated metapodials.
Paleobiology
- Likely a herbivore inhabiting open grassland or savanna‑like environments.
- Dental wear patterns suggest a diet dominated by grasses and possibly other tough plant material.
Discovery and research
- The genus was first described in the early 20th century based on fragmentary skeletal material.
- Subsequent finds have refined its classification within Notohippidae and clarified its relationships to other toxodontian notoungulates.
Significance
- Provides insight into the diversification of South American ungulate mammals during the Miocene.
- Illustrates convergent evolution of horse‑like morphology in unrelated mammalian lineages.
