Nannippus is an extinct genus of three-toed horse endemic to North America during the Miocene through Pleistocene, about 13.3—1.8 million years ago (Mya), living around 11.5 million years.[1][2][3] This ancient species of three-toed horse grew up to 3.5 feet (1.1 meters) and weighed between 165 pounds to 199 pounds, which was around the same size as a domestic sheep.[4][5]
Nannippus lived as far south as central Mexico (N. peninsulatus) to as far north as Canada (N. lenticularis), to California in the west, and North Carolina (N. lenticularis) and Florida (N. peninsulatus) in the east. Unlike its relatives, Nannippus, as well as all other three-toed horses endemic to North America, were browsers and mixed feeders that had diets consisting of C3 plants.[6]
^E. H. Sellards. 1916. Fossil vertebrates from Florida: A new Miocene fauna; new Pliocene species; the Pleistocene fauna. Florida State Geological Survey Annual Report 8:79-119
^W. W. Dalquest and T. J. Donovan (1973). "A new three-toed horse (Nannippus) from the late Pliocene of Scurry County, Texas". Journal of Paleontology. 47 (1): 34–45.