Orohippus (from the Greek ὄρος , 'mountain' and ἵππος , 'horse'
Description
It is believed to have
evolution from equids such as
Eohippus, as the earliest evidence for
Orohippus appears about 2 million years after the first appearance of
Eohippus.
The anatomical differences between the two are slight: they were the same size, but
Orohippus had a slimmer body, a more elongated head, slimmer forelimbs and longer hind legs, all of which are characteristics of a good jumper. Its teeth were
brachydont in height, but the development of flattened surfaces and shearing
on their molars suggests they were more a browser than a
frugivore.
[Kitts, D. B. 1957. A Revision of the Genus Orohippus (Perissodactyla, Equidae). American Museum Novelties, 1864:1–40.] The outer toes of
Eohippus are no longer present in
Orohippus, hence on each forelimb there were four fingers (toes) and on each hind leg three toes.
Species of Orohippus has also been referred to Protorohippus.
See also
-
Evolution of the horse
-
Horse
Notes
