Dental News - Discovery of fossilised teeth in Indonesia stirs up old debate

Dental Tribune International

Thu. 17. August 2017

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BRISBANE, Australia: South East Asia is a key region for understanding the human dispersal out of Africa and down to Australia. It is a common consensus that all hominins would have had to pass through the region en route to the island continent. According to recent fossil teeth findings by researchers from the University of Queensland in Brisbane and Macquarie University in Sydney, this migration towards Australia may have occurred 20,000 years earlier than previously thought.

In a video posted online, the scientists follow the footsteps of Eugène Dubois, the paleoanthropologist famous for his discovery of “Java Man” (Homo erectus). In the Sumatran region of Indonesia, they re-enter a cave site called Lida Ajer, where in the late 1800s the Dutchman collected fossil teeth from other hominins. In the video, fossilised teeth are literally falling out of the cave wall, and at one point, a researcher picks up a mandibular molar from an ancient rhino and a molar from an orangutan and shows them to the camera.

According to Dr Gilbert Price of the University of Queensland’s School of Earth and Environmental Sciences, Dubois’s recovery of the human teeth was in itself very interesting, but no one had spent much time trying to determine its significance. As a result of the limited information and the time between the discovery in the late 1800s, there had been some controversy as to its importance. However, after an in-depth documentation of the cave and reanalysis of the specimens using a new dating program, it was confirmed that the teeth came from modern humans, Homo sapiens, and most interestingly that they dated to as long as 73,000 years ago.

Lead author Dr Kira Westaway, from Macquarie University’s Department of Environmental Sciences, said: “We employed a range of dating techniques from different institutions to establish a robust chronology that would, after 120 years, finally put an end to the uncertainty associated with the age and significance of these teeth.”

In a twist that may become a contentious topic at a later date, the findings from the study also suggest humans could have potentially made the crossing to Australia even earlier than the accepted 60,000–65,000 years ago.

Price stated that the dating of the cave site in West Sumatra provided the first evidence of rainforest use by modern humans. “Rainforests aren’t the easiest place to make a living, especially for a savannah-adapted primate, so it suggests that these people were ahead of the curve in terms of intelligence, planning and technological adaptation,” he said.

The study, titled “An early modern human presence in Sumatra 73,000–63,000 years ago”, was published online on 9 August in the Nature journal.