By Maina Kiarie
Homo rudolfensis, discovered by Richard Leakey’s team in 1972, lived in Eastern Africa (northern Kenya, possibly northern Tanzania and Malawi) about 1.9 million to 1.8 million years ago.The first fossils were discovered near the shores of Lake Rudolf (now known as Lake Turkana). The species was named by the Russian scientist V.P. Alexeev in 1986. Alexeev originally named the species Pithecanthropus rudolfensis, but the genus name Pithecanthropus was later replaced by Homo.
Between 2.0 and 1.5 million years ago four species lived in the Turkana Basin, northern Kenya: Homo rudolfensis, Homo habilis, Homo erectus, and Paranthropus boisei.
The height and weight of this species is currently unknown because no post-cranial fossils have been found to date. Homo rudolfensis had a braincase of around 700cc (about half the size of a modern human).
Homo rudolfensis had large and wider molars compared to Homo habilis. While their teeth were only slightly smaller than those seen in robust australopithecines, H. rudolfensis didn’t have the heavily-built jaw and strong jaw muscle attachments seen in robust early humans. These anatomical differences likely indicate different diets between H. rudolfensis and earlier australopithecine species capable of more powerful chewing.
Like other early Homo species, Homo rudolfensis may have used stone tools to process their food. However, because more than one species of early human lived at the time tool manufacture and use originated, it’s hard for scientists to be certain which species is responsible for the making and using the first stone tools. There are currently no stone tools found in the same layers as the H. rudolfensis fossils, but there are stone tools existing in the same time period that H. rudolfensis lived.