Image: Homo rudolfensis skull cast
The skull KNM-ER 1470 was discovered in 1972 in Kenya. It dates to about 1.7 million years old.
When the skull was discovered by Richard Leakey’s team, it was not attributed to a species, only a member of the genus Homo. In 1986, a Russian anthropologist gave the skull the species name Pithecanthropus rudolfensis. The genus name of Pithecanthropus was later dropped and replaced with Homo.
- Stuart Humphreys
- © Australian Museum
The skull was also once thought to be a member of the species Homo habilis but the differences compared to other Homo habilis skulls were considered too great.
There is large amount of controversy about the classification of H. rudolfensis. Debate continues as to whether these fossils should be named Homo rudolfensis, Kenyanthropus rudolfensis or Australopithecus rudolfensis, or left as Homo habilis.
In 2007, a team led by Timothy Bromage, an anthropologist at New York University, reconstructed the skull of KNM-ER 1470. The new construction had a more ape-like projecting jaw and a smaller brain size. They claim this new reconstruction makes it more like other Homo habilis specimens.