【考古学】ホモ・エレクトスの最後の姿

Fossil remains of Homo erectus found in Central Java, Indonesia, represent the last known occurrence of this ancient human species, a Nature study reveals. The findings help to clarify the position of this early hominin species in the evolution of humans from this region of the world.

Homo erectus, the first human species to walk fully upright, evolved around two million years ago and lived through much of the Pleistocene epoch. In the 1930s, 12 H. erectus skull caps and 2 lower leg bones were found in a bone bed 20 metres above the Solo River at Ngandong, Central Java. The fossils proved difficult to date because the stratigraphy of the site is complex and some of the original details of the location of previous excavations became confused, leading experts to propose a wide range of possible dates from 550,000 to 27,000 years ago. Having reanalysed the site and its surroundings, Russell Ciochon, Kira Westaway and colleagues now provide a definitive age for the bone bed of between 117,000 and 108,000 years old. These calculations indicate that the fossils are from the last known H. erectus individuals to have lived.

Intriguingly, the fossils are part of a mass death event that occurred upriver of Ngandong, which coincided with changing environmental conditions as open woodlands transitioned to a rainforest biome. According to the authors, the site of Ngandong was then formed when bodies and disarticulated remains were washed into the river and deposited downstream.