Morphological description, biometry and phylogenetic position of the skull of Ngawi 1 (East Java, Indonesia)

The skull of Ngawi 1 was discovered fortuitously in August 1987 on the left bank of the river Solo near the village of Selopuro (east Java, Indonesia). It is a complete, well preserved and strongly mineralized calvaria. The present article provides a complete description of this specimen. Its general morphological pattern is first considered; then, each anatomical complex is considered individually, allowing us a comparison with other Asian Pleistocene fossils. A broad biometric framework and a morphological database are both used to perform a cladistic analysis aiming at a more accurate determination of the phylogenetic position of this skull among 'Homo erectus'. This work confirms that Ngawi 1 is closer to the Ngandong-Sambungmachan series than to the Trinil-Sangiran series. Following the hypothesis of a young age (40,000 years) for the former series, the question is whether this skull belongs to a subspecies of Homo sapiens, as suggested by early authors, or to a separate species, Homo soloensis. An evolutionary process is suggested here, where Ngawi 1 belongs to a particular human group that is geographically and chronologically restricted. This Indonesian human group may have evolved at the same time as the Neandertals in Europe, an area which represented the westernmost end of Eurasia when Indonesia was its easternmost end. The question is raised as to whether insularity, that isolated this taxon, is comparable to the cool climate which isolated the Neandertals for thousands of years. If so, the Ngawi-Ngandong-Sambungmachan series might have evolved from an older, local Homo erectus population. On the other hand, due to local, drastic volcano-tectonic events that occurred 71,000 years ago, and catastrophic events 780,000 years ago, the first inhabitants of Java may have disappeared. According to this alternative hypothesis, Ngawi 1 could be one of the new invaders from continental Asia. Copyright (C) 2003 John Wiley Sons, Ltd.