 Leakey of Zinjanthropus Boisei", his account of the dig, was published in the January 1960 issue of "Current Anthropology".It was annotated by anthropologist Francis Clark Howell, who had been allowed to examine the Leakeys' Olduvai findings before public announcements of their discovery.Louis also wrote "Finding the World's Earliest Man" for the September 1960 issue of "National Geographic", estimating the fossil's age to be 600,000 years old.