Mrs Ples, the most perfect pre-human skull

“Mrs Ples” is the nickname for the perfect parts of a fossilized skull discovered by Dr Robert Broom on 18 April 1947 at Sterkfontein Caves near Krugersdorp in South Africa. The skull became known as Mrs Ples, derived from Plesianthropus, meaning almost human. It was described at the time as “the most perfect pre-human skull ever found”.

Mrs Ples is believed to be a distant relative of all humankind. It has a small cranium (similar in size to that of a chimpanzee), and it unquestionably stood upright, like humans. Robert Broom put Mrs Ples in the genus Plesianthropus, but it is now accepted as Australopithecus africanus, a species first described by Ramond Dart from a skull discovered at Taung.

The species is also known to be represented at Taung in South Africa’s North-West Province and at Makapansgat in the Northern Province. The discovery of Australopithecus africanus at various places in South Africa, confirmed Charles Darwin’s prediction that Africa was the continent from which human ancestors would be found. Darwin studied the skulls and skeletons of living primates, and on the basis of comparative anatomy, he reached the conclusion that, of all living primates, humans are closest to chimpanzees and gorillas.

Australopithecus africanus had an average height of 1.4 m, and the brain capacity is approximately 400 – 600 cc. Smaller incisor teeth and a slightly flatter face are also of significance. Sticks, and stones were most likely used to gather food.

By late September 2002 a new school of thought stated that Mrs Ples and the Little Foot skeleton (from Sterkfontein Caves) might be more than a million years younger than previously thought. They believe the Mrs Ples fossil to be between 2,5 and 2,8 million years old and the Little Foot skeleton over 3,3 million years old.

The Cradle of Humankind near Krugersdorp still focuses the attention of researchers around the globe to critically examine the South African hominid fossils. Recently, researchers have been critically examining the South African hominid fossils, and they are coming up with more questions than answers.”

Although Mrs Ples was discovered in 1947, she continues to be a subject of great interest and surprises are revealed as technology develops, permitting new ways of analysing the fossils. The Sterkfontein skull was at first considered female. Now most consider it to be male. UNESCO’s declaration of the Sterkfontein area as a World Heritage Site, linked to the recent discovery of a complete skeleton by Dr Ron Clarke, Stephen Motsumi and Nkwane Molefe of the University of the Witwatersrand, have contributed to growing public knowledge of the importance of Sterkfontein and adjacent sites.