Archaeologists have identified a new adult Homo erectus fossil in South Africa, pushing back the timeline for the species' appearance in the region by 200,000 years.

Researchers from La Trobe University and international partners have described 18 newly analyzed hominin fossils from the Drimolen Main Quarry in South Africa. Among the findings is the first adult Homo erectus fossil discovered at the site, dated to 2 million years ago. This discovery confirms that the species was present in southern Africa 200,000 years earlier than previously established by other adult fossils, such as those found in Dmanisi, Georgia.

Evidence of Microevolution in P. robustus

The study also examined fossils of the species P. robustus, which coexisted with Homo erectus in the same landscape. Researchers observed that P. robustus underwent microevolutionary changes between 2 million and 1.8 million years ago, developing larger teeth and more powerful chewing muscles to process tough, hard foods. These findings support the classification of the Drimolen P. robustus population as a distinct subspecies, P. robustus ukusa.

Insights from the Drimolen Quarry

The Drimolen Main Quarry, discovered in 1992, has yielded a significant number of hominin fossils, many of which remained unpublished until this recent study. The abundance of specimens allows researchers to track evolutionary changes in detail. While Homo erectus was evolving larger brains and smaller teeth, P. robustus maintained a smaller brain size and adapted to its environment through specialized dental and muscular development.