National Geographic : 1961 Oct
Exploring 1,750,000 Years Into Man's Past friend Zinjanthropus, whom Mary and I call "Zinj," or affectionately, "Dear Boy." In our extended excavations at the Zinj site - which involved removing thousands of tons of overlying rock - we found the two bones of our man's lower leg, the tibia and fibula, and some fragments of a second in dividual. We had hoped, among other things, to find the lower jaw of the 1959 skull, for with that we might be able to tell whether Zinjanthropus had the power of speech-a vital clue to his stage of development. In this we have been disappointed thus far, but even without the jaw we have learned a lot more about our man of thousands of centuries past. Readers of the earlier article will recall that we found the skull on an ancient living floor, an old campsite sealed between two geological layers. On that floor in 1960 we found more crude stone tools used for skin ning and cutting up carcasses, as well as bones of animals and the hammer stones used for cracking the bones to get at the marrow. These cracked bones confirmed our earlier belief that Zinjanthropus and his contempo raries lived largely by killing young animals - most of the bones are from immature spec imens. Interestingly enough, we found that later dwellers in Olduvai did not break open nearly so many bones, suggesting that they were not so short of food as Zinjanthropus was. Radio Links Campsite and Nairobi Much of this time I was forced to travel back and forth between the gorge and Nai robi, where I continued my duties as Curator of the Coryndon Museum. That is how I hap pened to learn of our exciting pre-Zinjan thropus find by wireless, for Mary and I kept in daily contact by radiotelephone. She and our 20-year-old son, Jonathan-who is cu rator of the snake park at the museum - ably directed the work in my absence. So much for Zinjanthropus. What about the new creature, the one we believe to be older than Zinj himself? I still find it hard Desert wasteland replaced lake waters, according to geological evi dence at the top of Bed I. Additional clues to the climatic change lie in the discovery of the fossils of many desert-loving rodents. Mired Dinotherium, an elephant like monster, attracts Chellean Stage 1 hunters, who possessed cutting tools but still lacked the weapons to bring down such a huge beast. In this peri od swamps succeeded deserts. Fallen giant, a prehistoric ram (page 584), lies victim of a Chellean bola (painting, pages 578-9). With this new weapon, Chellean man at last could tackle most big game.