Equus—One-toed Horses // Nannippus—Gazelle-horses
Although horses had most of their evolutionary history in North American, occasionally sending emigrants to Eurasia and South America, North American diversity had decreased by the beginning of the Pleistocene to only two genera: Equus and Nannippus. The former genus lasted to the great megafaunal extinction at the end of the Pleistocene, but the latter apparently was extinct by 2.2 mya (Morgan and Lucas 2003).
Morgan and Lucas 2003.
Last Update: 30 Aug 2009