The Zinjanthropus skull, also known as Australopithecus Zinjanthropus Boisei or Nutcracker Man, Professor Leakey and his wife began their research in the Olduvai Gorge in 1931 and in 1959 Mary Leakey found fragments of a skull, part of a male hominid whom they called Zinjanthropus. Tanzania ***. Prehistoric. Lower Paleolithic / 1,750,000 BC. Olduvai Gorge.