Despite Charles Darwin’s much-debated assertion that Africa was the cradle of humankind, the first scientists to study human evolution focused their efforts in Europe. Important discoveries included Neanderthal Man (classified either as a subspecies of modern man, Homo sapiens neanderthalensis, or its own species, Homo neanderthalensis) in 1856 and Cro Magnon (Homo sapiens sapiens) in 1868.
Later efforts spread to Asia, where Eugene Dubois discovered Java Man (Homo erectus) on Java in 1891. However, the search did not reach Africa until 1924, when quarry workers uncovered the Taung Child, named Australopithecus africanus by Raymond Dart, who believed this species represented a missing link between ancient apes and modern humans.
Raymond Dart Learns Anatomy
Raymond Dart was born the fifth of nine children in Queensland, Australia, in 1893. After attending the University of Queensland on a scholarship, he studied medicine at the University of Sydney and evolutionary human brain anatomy at St. Andrew’s College.
During World War I he traveled to Europe, serving in the Australian Army Medical Corps. After the war he worked at the University of London until moving to the University of Witwatersrand in Johannesburg, South Africa in 1922.
As the head of the anatomy department, Dart spearheaded the effort to build the college’s comparative fossil collection. Such an assemblage was critical for him to properly teach anatomy and the similarities and differences between organisms. Dart involved his students in the effort, at one point offering a 5 pound prize to the one bringing him the best bones.
Dart Acquires Fossil Hominid Bones from Limestone Mine
One of Dart’s most enthusiastic students was also the only female in his class, Josephine Salmons. In 1924 Salmons visited her friend E.G. Izod, who helped operate the Northern Lime Company near Taung in today’s Botswana. Salmons noticed what she believed to be a baboon skull on Izod’s mantelpiece.
The next day Salmons told Dart about the fossil, which had been collected at Izod’s mine. Dart doubted it was a baboon, since fossil primates were unknown from that far south in Africa. However, the next day Salmons borrowed the specimen from Izod and brought it to Dart. To his surprise, the skull in fact was a baboon’s.
Dart immediately consulted with his University of Witwatersrand colleague and geologist R.B. Young, who was planning a trip to study the lime deposits near the Northern Lime mine. At Dart’s request, Young visited the mine and requested that further fossil finds be sent to Dart. On this trip, Young met an old miner named M. de Bruyn, an amateur fossil collector who had filled two boxes with ancient bones. Young arranged for the boxes to be sent to Dart, hopeful that his colleague would find the contents useful.
The eagerly anticipated boxes arrived at Dart’s home but at a most inopportune time. Dart and his wife were hosting a friend’s wedding that day and the boxes arrived just as Dart was dressing for the ceremony.
Dart’s wife pointedly told him to finish dressing and forget about the fossils until the next day. Dart couldn’t control his excitement about the boxes; as soon as his wife finished her admonitions and left the room, he tore the boxes open and examined their contents.
Hoping for more primate fossils, Dart was disappointed after opening the first box, as it contained only fossilized egg shells, turtle shells and some bones. However, as soon as he opened the second box he became elated. Sitting on top was an endocranial cast of a primate, produced millennia ago when rock filled a skull and essentially created a copy of the brain, revealing details such as blood vessels and convolutions. He soon discovered a perfectly matching chunk of rock that fit the cast. Dart reasoned that this rock contained the face of the skull.
Raymond Dart Names Australopithecus africanus, a Missing Link
Dart realized the skull was unique, as it was much larger than any known baboon or chimpanzee but not big enough to be an ancient human. Perhaps, he thought, this specimen represented a missing link between ancient apes and modern humans. To be sure, he would have to clean the matching rock to expose the skull’s face.
Dart wasn’t experienced at preparing fossils, but he nonetheless took on the task of painstakingly cleaning the rock away from the bone. He propped the specimen in sand and gently chiseled away the matrix. He then sharpened his wife’s knitting needles and used them for detailed cleaning. Dart needed 73 days to expose the front of the face, which he realized represented a youth since the permanent molars were just starting to erupt.
Dart’s expertise in anatomy helped him determine that the specimen was unlike any previously described and, in fact, a missing link. In addition to the unusual size of the skull (too big for a chimp or baboon, too small for a human), the canine teeth were more like humans than apes. Moreover, the foramen magnum (hole in the skull through which brainstem passes) was in the bottom of the skull rather than at the back, indicating the creature walked upright.
The specimen soon became known as the Taung Child or Taung Baby, and Dart gave it the scientific name, Australopithecus africanus, literally meaning the “southern ape of Africa”. For decades the scientific community believed the new species was merely an ape. Not until the 1950s was it universally recognized as belonging to the human line of evolution.
References
Dart, Raymond. 1925. “Australopithecus africanus: The Man-Ape of South Africa”. Nature, v. 115.
Fagan, Brian. 1996. Eyewitness to Discovery. Oxford University Press.
Kevin Schindler - I have worked at scientific institutions for more than 20 years written more than 200 articles about science, history, and baseball.
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