In October 1993, an international team of paleontologists discovered a partial hominine mandible near Lake Malawi. The mandible was less robust than that in australopithecines and the cheek teeth smaller, indicating that it was closely associated with Homo. The authors named this specimen Homo rudolfensis, a contemporary of Homo habilis which was found at Lake Turkana. The Malawi hominid, together with other fauna that are characteristic of Eastern Africa, indicate significant fauna movement between the two regions.

Homo rudolfensis had a flatter, broader face and broader postcanine teeth with more complex crowns and roots, and thicker enamel. This species also had a larger cranium. All the non-australopithecine speciments found at Olduvai Gorge are known to be Homo habilis, whereas the ones found at Lake Turkana can be divided between Homo habilis and Homo rudolfensis.

There is now a general agreement that two species of Homo coexisted 2 million years ago. Although the taxonomic distinction is based principally on cranial and dental characters, it is useful to think of Homo habilis as a smaller-brained creature with an archaic postcranium, and Homo rudolfensis as larger-brained with a more modern postcranium. Which of the two (if either) gave rise to later Homo is still being debated. Homo rudolfensis appears to have a good claim based on brain size and the more modern postcranium, but some insist that its facial and dental anatomy disqualify it from this role.

This table shows the main morphological differences between the two main members of the early Homo family; Homo habilis and Homo rudolfensis.