American Mammals: Their Lives, Habits, and Economic Relations. Written by W. J. Hamilton Jr. 1939.
Internet Archive
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American Mammals: Their Lives, Habits, and Economic Relations. Written by W. J. Hamilton Jr. 1939.
Internet Archive
Neohipparion affine, an early horse from the Neogene of North and Central America. Fossil evidence of horses shows an interesting transition from small early four-toed forms to our large modern one-toed horses. Neohipparion, with a medium-sized body and three toes per foot, sits in the middle of this grade.
Fossil horses from the Ashfall Fossil Beds in Nebraska, a site whise richness of mammal fossils is attributed to a large Yellowstone eruption. Horse remains are plentiful, with five genera known to be present. They are depicted above in the following order: Pseudohipparion, Neohipparion, Cormohipparion, Protohippus, and Pliohippus. The first three genera are three-toed, while the last two bear single hooves.
Source
Florida Museum of Natural History