This silicified tuff bifacial centripetal core is from Kobatuwa, So’a Basin, Flores, Indonesia. The stone artefacts at the Kobatuwa site are dated to ca. 700,000-800,000 BP. It was made by an ancestor of Homo floresiensis. A flake was discovered from the same excavation trench that conjoins onto the large scar on this core.
The artefact in this model is from Kobatuwa, near the site of Mata Menge, and dates to ca. 700,000-800,000 BP. The artefact is from Kotak 14, Layer H, artefact number 82. The core is a river pebble reduced bifacially around the perimeter. Most of one face was removed by a single blow, a strategy reminiscent of the Levallois method. The flake from this blow was also recovered, and it conjoins onto the scar on the core. This is the oldest conjoin yet discovered in Southeast Asia. The intention was probably to produce sharp-edged flakes to use as tools.
Artefact on loan to Archaeology and Palaeoanthropology, University of New England.
Homo floresiensis was discovered in 2003 by a joint Australian/Indonesian research team—led by Mike Morwood, then at the University of New England, and R. P. Soejono, National Research Centre for Archaeology, Indonesia—in Liang Bua cave near Ruteng on the island of Flores. The skeleton was determined to be a new species within the genus Homo. This was a controversial assessment at the time but is now accepted by the scientific community. The hominin was unusual because it stood just over one meter tall with the brain size of a chimpanzee, yet various traits of the skeleton place it within the genus Homo. Subsequent research discovered teeth and bone fragments dating to ca. 700,000 BP at the site of Mata Menge, in the So’a Basin east of Liang Bua, and stone tools dating to 1 million years at the nearby site of Wolo Sege; these finds show that H. floresiensis and its ancestors were long-term residents on the island. The hominin species likely arrived on Flores from the island of Sulawesi to the north. There are two competing hypotheses for the hominin’s origin. One view is that it descended from Homo habilis or an Australopithecine that found its way onto Flores. However, those species lived in Africa, and there is no evidence for them between Africa and Flores. For this reason, it is not considered the most parsimonious explanation. Another view is that H. floresiensis descended from Homo erectus, which is known to have lived on the nearby island of Java during this timeframe. In this hypothesis, H. erectus arrived on Flores and its body size shrank through time, as often happens with large-bodied animals that are isolated on small islands. The contrary view to that hypothesis is that shrinking alone cannot account for the peculiar mixture of primitive and derived traits seen in the H. floresiensis skeleton.
An important aspect of the behaviour of H. floresiensis is that the species relied on stone tools throughout its evolutionary history on Flores, as attested by the tool assemblages recovered by archaeologists from Liang Bua and various early sites in the So’a Basin. Stone tool-making was retained despite the possibility that profound changes occurred to the hominin’s brain size and neural organisation as evolution selected for a much smaller body size. If so, this attests to the crucially important role stone tools played in the ongoing survival of these unusual hominins. H. floresiensis was skilled at removing flakes from a core, but the overall approach to stone-flaking was relatively simple. It appears that the hominins were mostly interested in using hard-hammer percussion to make sharp-edged flakes to use in various tasks, although the presence of retouched cobbles and flakes with pick-like projections may indicate a special use for certain tools.