In 1959, "P. boisei" was discovered by Mary Leakey at Olduvai Gorge, Tanzania (specimen OH 5). Her husband Louis named it "Zinjanthropus boisei" because he believed it differed greatly from "Paranthropus" and "Australopithecus". The name derives from "Zinj", an ancient Arabic word for the coast of East Africa, and "boisei", referring to their financial benefactor Charles Watson Boise. However, this genus was rejected at Mr. Leakey's presentation before the 4th Pan-African Congress on Prehistory, as it was based on a single specimen. The discovery of the Peninj Mandible made the Leakey's reclassify their species as "Australopithecus (Zinjanthropus) boisei" in 1964, but in 1967, South African palaeoanthropologist Phillip V. Tobias subsumed it into "Australopithecus" as "A. boisei". However, as more specimens were found, the combination "Paranthropus boisei" became more popular.