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Hipparion or Three-Toed Horse

Amongst the many mammalian groups present at Langebaanweg are included a substantial sample of well preserved skeletal remains of the hipparion. The species found at Langebaanweg is called Eurygnathohippus hooijeri (Bernor and Kaiser, 2006). A comparison with a number of Eurasian and African hipparions has revealed that Eurygnathohippus hooijeri exhibits characters of the skull and basic proportions of the postcrania that suggest it is descended from the hipparion species Cormohipparion. This is an Old World species of hipparion which is of early Miocene age. The Langebaanweg hipparion is particularly similar to Cormohipparion africanum from the Late Miocene horizons of Bou Hanifia, a fossil site in Algeria.

The Langebaanweg hipparion is distinguished by having exceptionally high crowns on its teeth and it is thought that its diet may have been similar to that of local populations of the extant plains zebra (Equus burchelli) from Kenya and Botswana, and that it probably occupied a similar dietary niche to this zebra, prior to the arrival of modern horses in Africa. The Langebaanweg hipparion is also distinguished from other species in that it was larger, and less advanced in the length and thickness of its metapodials. These features indicate that Eurynathohippus hooijeri was advanced, for an hipparionine horse, in its cursorial abilities.

Fossil Relatives: The closest relative to Eurygnathohippus hooijeri is the hipparion species Eurygnathohippus feibeli which is found at the site of Lothagam Upper Nawata in Kenya, and the Middle Awash (The Middle Awash paleoanthropological research area extends along both sides of the modern Awash River in the Afar Depression of Ethiopia) in the latest Miocene.

Acknowledgements:

Our thanks to Dr Raymond Bernor for supplying the above information.

Reference:

RAYMOND L. BERNOR & THOMAS M. KAISER Systematics and Paleoecology of the Earliest Pliocene Equid, Eurygnathohippus hooijeri n. sp. From Langebaanweg, South Africa. Mitt. hamb. zool. Mus. Inst. Band 103 S.149-185 Hamburg, Dezember 2006.