Sifrhippus is an extinct genus of equid containing the species S. sandrae and S. grangeri. Sifrhippus is the oldest known equid, and its fossils come from the earliest moments of the Eocene of the Bighorn Basin, Wyoming. A 2012 study found Arenahippus to be synonymous with Sifrhippus.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0