Name: Eohippus
(dawn horse).
Phonetic: E-oh-hip-pus.
Named By: O. C. Marsh. - 1876.
Synonyms: Eohippus validus, Hyracotherium
angustidens, H. a. angustidens, H. a. etsagicum, H.
vasacciensis, H. v. vasacciensis, H. cusptidatum, H.
seekinsi, H. loevii, Orohippus angustidens, Orohippus
cuspidatus, Orohippus vasacciensis, Lophiotherium vasacciense.
Classification: Chordata, Mammalia,
Perissodactyla, Equidae.
Species: E. angustidens
(type).
Diet: Herbivore.
Size: About 30 centimetres high at the shoulder.
Known locations: Mexico. USA.
Time period: Ypresian of the Eocene.
Fossil representation: Numerous individuals of
varying levels of completeness.
Eohippus
is a classic prehistoric mammal, dubbed as one of the earliest and
smallest horses ever to live. There has in the past been some
taxonomic confusion over the validity of the genus, and at one time
Eohippus was actually regarded as belonging to
another genus named
Hyracotherium.
Later thought has cast doubt upon the correctness of
such thinking, and now once again Eohippus is
regarded as being
distinct from Hyracotherium.
Eohippus
was tiny, and most individuals seem to have averaged a size of about
thirty centimetres high at the shoulder. Most early horses seem to
have fed as browsers, selectively feeding upon low growing plants.
Such an environment and small size would have meant that Eohippus
could hide amongst the undergrowth to try and avoid the eyes of hungry
predators such as creodonts and early nimravids.
Further reading
- Notice of new Tertiary mammals. V. - American Journal of
Science 12(71):401-404. - O. C. Marsh. - 1876.
- Quo vadis eohippus? The systematics and taxonomy of the early
Eocene equids (Perissodactyla). - Zoological Journal of the
Linnean Society. 134 (2): 141–256. - D. J. Froehlich
- 2002.
- Fossil Horses--Evidence for Evolution. - B. J. MacFadden
- 2005.