Homo rudolfensis

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Homo rudolfensis
Fossil range: Pliocene

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Hominidae
Genus:	Homo
Species:	H. rudolfensis

Binomial name

†Homo rudolfensis
Alexeev, 1986

Homo rudolfensis is a fossil hominin species discovered by Bernard Ngeneo, a member of a team led by anthropologist Richard Leakey and zoologist Meave Leakey in 1972, at Koobi Fora on the east side of Lake Rudolf (now Lake Turkana) in Kenya. The scientific name Homo rudolfensis was proposed in 1986 by V. P. Alexeev for the specimen Skull 1470 (KNM ER 1470). Skull 1470 has an estimated age of 1.9 million years.

Originally thought to be a member of the species Homo habilis, the fossil was the center of much debate concerning its species. Assigned initially to Homo habilis, the skull was at first incorrectly dated at nearly three million years old. This estimate, however, caused much confusion: the date would have made the skull older than any known australopithecine, from which Homo habilis is thought to have descended. The differences in this skull, when compared to others of the Homo habilis species, are too pronounced, leading to the presumption of a Homo rudolfensis species, contemporary with Homo habilis. It is not certain if H. rudolfensis was ancestral to the later species in Homo, or if H. habilis was, or if some third species yet to be discovered was.

As in the case of H. habilis, there is large amount of controversy about the classification of H. rudolfensis into the Homo genus. Although no reliably associated postcranial remains have been discovered for H. rudolfensis, it is thought that — like H. habilis — H. rudolfensis lacked many of the features unique to later hominins (that is, creatures that include humans and their ancestors), such as slim hips for walking long distances, a sophisticated sweating system, narrow birth canal, legs longer than arms, noticeable whites in the eyes, smaller hairs resulting in naked appearance and exposed skins, etc.^{[citation needed]} Many scientists think H. rudolfensis to be more ape-like despite its large brain and bipedal locomotion.^{[citation needed]}

In March 2007, a team led by Timothy Bromage, an anthropologist at New York University, reconstructed the skull of KNM-ER 1470. The new construction looks very ape-like and the cranial capacity based on the new construction is downsized from 752 cubic centimeters to about 526 cm³. Bromage said his team’s reconstruction includes biological principles not known at the time of the skull’s discovery, which state that a mammal’s eyes, ears and mouth must be in precise relationships relative to one another.^[1]