Kathleen Kuman

A sharp focus on our human ancestors’ tools

“Working at Sterkfontein and Swartkrans is exciting because these sites have a special aura about them,” says Dr Kathleen Kuman, an archaeologist who specialises in early stone tools, of her workplaces.

“Exploring their long-buried mysteries makes me feel connected to the past, with a deeper appreciation for the minds and abilities of the early tool-making hominids that used the land and its resources.”

And then there are her protégés, the many students she has mentored over the years (among them the current research director of the Sterkfontein Caves, Professor Dominic Stratford): “I also love helping our postgrad students develop their abilities and watching them grow in confidence as they progress in their studies.”

Kuman arrived at Sterkfontein more than 30 years ago, having been asked to study its archaeology by Professor Phillip Tobias.

“As I have always been keen to study the links between early human and cultural evolution, it was exciting to join the Sterkfontein team in 1991. When Ron Clarke extended the excavations deeper in the western half of the deposits exposed at the surface, it was even more exciting for us to discover the earliest tools in Southern Africa, which I published (about) in 1994 as an Oldowan industry,” she says.

Sterkfontein projects have included research on stone tools, site formation, the use of site contents for understanding the spatial relationship of infills, cosmogenic dating and, of course, supervising and co-supervising many postgraduate students on Sterkfontein’s archaeology, fauna and stratigraphy.

“My collaboration on projects at Swartkrans began in 2005, when Travis Pickering renewed excavations at the site. My primary work there has been on the archaeology of the earliest stone tools in the Member 1 Lower Bank and its dating with cosmogenics, along with the supervision of several postgraduate students,” says Kuman.

Accurately dating finds, particularly using modern tools such as cosmogenic dating, have been vital to confirming the Cradle of Humankind’s importance: “While the Cradle sites have produced many historical firsts, they have been overshadowed in recent decades by East African sites in open-air contexts that have been much easier to date with volcanic materials. Now that our team is achieving success with cosmogenic dating, the significance of the Cradle sites in the greater picture of early human evolution in Africa is becoming clearer.”

In this context, the Oldowan tools at Sterkfontein were dated in 2015 along with cosmogenic dating specialist Darryl Granger, and estimated an age of ~2.2 Ma. Equally significant, she says, was the publication in 2022 of an age of ~3.4 Ma on the main Australopithecus deposit (Member 4) at Sterkfontein, which has long been debated. Oldowan artefacts at Swartkrans, associated with Paranthropus and other fossil fauna, were in 2021 dated to ~2.2 Ma.

“Finally, excavations [still unpublished] of Middle Stone Age [MSA] deposits in a new part of the [Swartkrans] site complex are significant because of their good context, making this the best context for MSA in the Cradle sites. Although MSA was long known in the main site, this new materia (now with associated fauna) comes from a recently discovered small cave below the main site, named APS after our technician Andrew Phaswana, who brought it to our attention,” says Kuman.

Cosmogenic dating was also vital to establishing that the Little Foot skeleton found at Sterkfontein, the most complete ever discovered, is ~3.67 Ma old. “The series of papers on Little Foot and its stratigraphy our team published in 2019-2021 has been of major significance for Sterkfontein, and additional papers are still in preparation,” says Kuman.

Little Foot’s discovery had been anticipated, Kuman recalls: “Alun Hughes [Professor Tobias’s first excavations director] told us he had a recurring dream of breaking into a cave and finding a complete skeleton. Alun died in 1992 and five years later, Ron Clarke, Stephen Motsumi and Nkwane Molefe discovered the location of the Little Foot skeleton in rock-hard deposits in a lower cave called the Silberberg Grotto, which made Alun’s dream a reality.”