The first identified jawbone, Peninj 1, was discovered Lake Natron just north of Olduvai Gorge in 1964. Especially from 1966 to 1975, several more specimens revealing facial elements were reported from the Shungura Formation, Ethiopia; Koobi Fora and Chesowanja, Kenya; and Omo and Konso, Ethiopia. Among the notable specimens found include the well preserved skull KNM-ER 406 from Koobi Fora in 1970. In 1997, the first specimen with both the skull and jawbone (and also one of the largest specimens), KGA10-525, was discovered in Konso. In 1999, a jawbone was recovered from Malema, Malawi, extending the species' southernmost range over from Olduvai Gorge. The first definitive bodily elements of "P. boisei" associated with facial elements, OH 80 (isolated teeth with an arm and a leg), were discovered in 2013. Previously, body remains lacking unambiguous diagnostic skull elements had been dubiously assigned to the species, namely the partial skeleton KNM-ER 1500 associated with a small jawbone fragment. OH 80 was also associated with Oldowan stone tools. In 2015, based on OH 80, American palaeoanthropologist Michael Lague recommended assigning the isolated humerus specimens KNM-ER 739, 1504, 6020, and 1591 from Koobi Fora to "P. boisei". In 2020, the first associated hand bones were reported, KNM-ER 47000 (which also includes a nearly complete arm), from Ileret, Kenya.