Merychippus [SEP] parent taxon
Merychippus
Merychippus is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene, 15.97–5.33 million years ago. It had three toes on each foot and is the first horse known to have grazed.
Discovery and naming.
"Merychippus" was named by Joseph Leidy (1856). Numerous authors around the turn of the century assigned the type species – "Merychippus insignis" – to "Protohippus", but this is ignored. It was assigned to Equidae by Leidy (1856
Scaphohippus
Scaphohippus is an extinct Miocene genus of equine, with two known species, known from fossils found in California, New Mexico, Montana, and Nebraska.
History.
Both species in the genus were originally described as members of the wastebasket taxon "Merychippus" in the 1915 by John Merriam. The genus was described from specimens found in the Barstow Formation of southeast California. Specimens of "Scaphohippus" were medium-sized horses with hypsodont (high-crowned) teeth.
Phylogenetic relationships.
The genus