One set of fossil remains (OH 62, for "Olduvai Hominid specimen 62"), discovered by Donald Johanson and Tim White in Olduvai Gorge in 1986, included the important upper and lower limbs, specifically the humerus and femur. Their finding stimulated some debate at the time. Locomotor affinities of OH 62 have been assessed primarily on the basis of its forelimb to hind limb proportions, which are known to be associated with locomotor behavior among living primates. Initial analyses concentrated on comparisons to the Australopithecus afarensis A. L. 288-1 ("Lucy"). In most dimensions—measured or estimated—the OH 62 upper limb remains equaled or exceeded those of A. L. 288-1, while its lower limb remains (principally the femur) appeared to be smaller. In particular, using a length estimate for the humerus of 264 mm, and a length estimate for the less complete femur of ‘‘no greater than that of A. L. 288-1 (280 mm),'' a possible humerofemoral length index is close to 95%, which is more like that of modern chimpanzees (averaging about 1. 00) than modern humans (averaging about 0. 72). In this sense, it was more ‘‘primitive'' than A. L. 288-1, with a length index of 0. 85.
These characteristics resulted in this species’ placement into the human genus, Homo. However, this classification is now being debated because new fossil discoveries show this species shares some important physical similarities with members of the Australopithecus genus.