A team of scientists, led by Prof Andy Herries, recently discovered three different hominin species — Australopithecus, Paranthropus, and the earliest-known hom*o erectus — lived in the same place at the same time.
Prof Andy Herries, a paleoanthropologist at La Trobe University in Melbourne, Australia, led the groundbreaking research that has established the newly excavated H. erectus fossil as the oldest definitive specimen ever discovered. The fossils from the three different hominin species were found in Drimolen, one of several ancient caves in the Cradle of Humankind in South Africa (a United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage Area).
This is the first time we see an overlap between the end of Australopithecus and the beginning of H. erectus, enriching the story of early human evolution and dispersal. Never before has dating demonstrated that H. erectus, Paranthropus, and Australopithecus lived during the same time period between 2.04 million and 1.95 million years ago. H. erectus is ancestral to H. heidelbergensis, a common ancestor which we share with Neanderthals, found in Eurasia, H. floresiensis in Indonesia and the ‘Denisovans’ in Siberia.
Previously, it was thought that the australophithecine phase didn’t overlap with the human phase, which begins with H. erectus. The australopithecine phase saw many species of early bipedal but still largely arboreal (tree-dwelling) and predominantly ape-like creatures widespread in Africa from about 4-2 million years ago. H. erectus displays distinctly human anatomy, albeit with a skull dominated by a huge brow ridge, increased dietary range and increased behavioural complexity including the use of simple tools.
The hominin crania discovered at Drimolen are evidence of contemporaneous living of H. erectus, Paranthropus, and Australopithecus. The H. erectus cranium consists of many small skull fragments which were pieced together by the team. Extraordinarily the team found some of the fragments in an old collection and they were able to fit these to the newly excavated pieces. Initially the skull fragments were thought to belong to a baboon. But when the team put the pieces together they could tell that it was from a 2 to 3 year old juvenile, because the cranial sutures were at an early stage of fusion and they could tell it wasn’t a juvenile baboon from the cranial capacity.
The cranial capacity was estimated by constructing a virtual endocast (internal cast of the cranial vault), which is used in the study of brain development. They also used the estimated brain size to rule out other hominins as cranial capacity exceeded the brain sizes of juvenile Australopithecus and Paranthropus. They knew then that they had a juvenile H. erectus.
What is the importance of finding this H. erectus fossil in South Africa? The answer is multifaceted but the location of this earliest known occurrence of H. erectus in South Africa also argues against an Asian origin for H. erectus, as previously suggested. This is strong evidence that H. erectus evolved in Africa before very quickly journeying to the Caucasus by 1.8 million years ago and China and Java by 1.6 million years ago.
Today, hom*o sapiens is the only human on earth but 70,000 years ago there were at least four kinds of humans – H. sapiens in Africa, Neanderthals in Eurasia, hom*o floresiensis in Indonesia and the ‘Denisovans’ in Siberia. This new finding suggests our earliest human ancestor also inhabited a pre-populated landscape and lived alongside Paranthropus and Australopithecus. This creates a much more dynamic image of our evolution in Africa.
Dr Amy Mosig Way, Scientific Officer, Archaeology, Australian Museum Research Institute; and Conjoint Lecturer, School of Philosophical and Historical Inquiry, Faculty of Arts and Social Sciences, University of Sydney.
Professor Andy I.R. Herries, Head of Dept. of Archaeology and History, La Trobe University, Melbourne, Australia
More information:
- Herries, Andy I. R., Jesse M. Martin, A. B. Leece,J ustin W. Adams, Giovanni Boschian, Renaud Joannes-Boyau, Tara R. Edwards, Tom Mallett, Jason Massey, Ashleigh Murszewski, Simon Neubauer, Robyn Pickering, David S. Strait, Brian J. Armstrong, Stephanie Baker, Matthew V. Caruana, Tim Denham, John Hellstrom, Jacopo Moggi-Cecchi, Simon Mokobane, Paul Penzo-Kajewski, Douglass S. Rovinsky, Gary T. Schwartz, Rhiannon C. Stammers, Coen Wilson, Jon Woodhead, Colin Menter. 2020. ‘Contemporaneity of Australopithecus, Paranthropus, and early hom*o erectus in South Africa’. Science 368 (6486): eaaw7293. https://science.sciencemag.org/content/368/6486/eaaw7293
- Stringer, Chris. 2011. The origin of our species. Penguin; UK.
