Science: Old Heads

In November 1924 a blast was fired in a limestone quarry near Taungs in Bechuanaland, South Africa. In the material that tumbled to the foot of the cliff were fossil fragments from a cave which the blast had exposed. The manager gathered the fossil-bearing chunks together, handed them to a Johannesburg geologist named Young who was stopping by on business. Dr. Young took them to Dr. Raymond Arthur Dart, professor of anatomy at the University of Johannesburg. Laboriously scraping away the rocky mineral, Professor Dart uncovered a small, fragmentary skull with the face almost intact. The scientist quickly realized that he had in his hands one of the most important evolutionary finds since the discovery of Pithecanthropus erectus, the ape-man of Java. Geological evidence indicated that the skull, whose owner was christened Australopithecus, was 500,000 to 1,000,000 years old.

Much of the uncertainty over the status of Australopithecus was due to his extreme youth. He was not more than six years old when he died. The jaw contained 20 milk teeth, four permanent teeth. Dr. Dart placed him at the base of the human evolutionary stem. But Sir Arthur Keith, while admitting certain manlike features, put him on the same branch with gorillas and chimpanzees, though on a separate twig. After several years the lower jaw was detached from the upper, and the crowns of the milk teeth were seen to be almost wholly human in form. Dr. William King Gregory of Columbia, a world authority on the dental development of primates, located the Taungs skull close to the point of human origin.

One of those who agreed with Professor Dart from the first in placing Australopihecus "in or near the line by which man las arisen" was Dr. Robert Broom, paleontologist of the Transvaal Museum in retoria. Last July another blast in another limestone quarry, this time at Sterkfontein, turned up another fossil brain case. The manager, urged by Dr. Broom to keep his eyes peeled for a Taungs ape, landed this to the scientist. Feverish earch disclosed the upper face, the skull base, the right jawbone with three teeth, a detached molar. Last week in Nature appeared a letter from Dr. Broom describing his find, with three photographs and a drawing.

To Dr. Broom's joy the Sterkfontein skull was that of an adult, with fairly heavy brow ridges and a brain capacity of about 600 cc. He found some resemblances to the Taungs skull and some differences, therefore put his fossil in the same genus with Australopithecus but in a different species. Name: Australopithecus transvaalensis Broom. One molar which he was able to examine closely showed close affinities to Dryopithecus, a well-known genus of extinct apes. It is from a generalized type of Dryopithecus that most anthropologists believe man evolved.