MIDDLE PLEISTOCENE FAUNAL TURNOVER AND COLONIZATION OF FLORES (INDONESIA) BY HOMO-ERECTUS

Several stone artefacts have been found in a fluvial sandstone layer b elonging to the Ola Bula Formation, near Mata Menge in the Ngada Distr ict, West Central Flores, Indonesia (figure 1). Paleomagnetic measurem ents indicate a polarity change from reverse to normal a few meters un derneath the artefact-bearing layer. This transition represents the Ma tuyama-Brunhes boundary, indicating an age of slightly less than 0.73 Ma BP for the artefact-bearing layer. This relatively old age suggests that the artefacts are the work of Homo erectus. The artefacts consis t of several fractured basalt pebbles and flakes and were found in ass ociation with fossil remains of Stegodon trigonocephalus florensis Hoo ijer and freshwater mollusca. An older fauna association occurs at the base of the Ola Bula Formation. It contains a pygmy Stegodon, a large tortoise and Varanus komodoensis Ouwens. Though distinct in compositi on, both successive faunas are characteristic for island conditions. T hese results suggest that Homo erectus was able to cross a water barri er to reach the paleo-island of Flores.