Morphological studies on the processed of arrival, evolution, and possible extinction of Javanese Homo erectus

关于“爪哇直立人的到来”，我们着重于相对丰富的下颌和牙齿材料的形态学分析。爪哇古人类的进化和系统发育地位一直存在争议，专家们表达了不同的观点，从“与南方古猿相当”到“与周口店直立人相当”，对现有化石材料缺乏全面、系统的比较分析可能是造成这种混乱的主要原因之一。因此，我们研究了大多数现有的化石材料，并考虑了这些化石的最新年代信息。研究结果表明了一种介于上述两种极端观点之间的观点：最古老的爪哇人科动物与肯尼亚和其他地区已知的非洲早期直立人最为相似。与此同时，我们的分析表明，桑吉兰原始人不是同质的，而是两种形态不同的。关于“进化和灭绝”，我们把重点放在头盖骨上，因为这一元素在爪哇的更新世晚期人科动物遗骸中占主导地位。尽管有丰富的化石标本，但以前的研究存在持续的局限性：基于整个收集的一小部分进行分析，和/或使用不同研究人员以不同方法发表的测量数据。我们对现有的大部分爪哇颅骨标本进行了自行观察和测量，并建立了自己的基于统一方法的详细测量数据集。结果表明，“早期”爪哇直立人（Trinil, Sangiran）与“晚期”爪哇直立人（Ngandong）在形态上存在显著差异，三峰玛坎的3个颅骨在形态特征上大体介于早期和晚期爪哇直立人之间。这支持Java的系统发育连续性。与此同时，在赣东颅骨中发现的一些形态特化表明，该地区直立人与智人种群之间存在不连续。少

Concerning the "arrival of Javanese Homo erectus" we focused on morphological analyses of the relatively abundant mandibular and dental materials. Evolutionary and phylogenetic position of the oldest Javanese hominids has been controversial and various views are expressed by specialists, ranging from "comparable to australopithecines" to "comparable to Zhoukoudian Homo erectus" Lack of comprehensive, systematic comparative analyses on the existing fossil materials is probably one of the major reasons of this confusion. We therefore investigated the majority of the existing fossil materials, taking latest chronological information for these fossils into consideration. The results suggest a view which is intermediate between the above two extreme views : the oldest Javanese hominids are most similar to early Homo erectus from Africa known from Kenya and other regions. At the same time, our analyses indicate that the Sangiran hominids were not homogeneous, but two morphologically distinct … More chronological groups are recognized.Regarding the "evolution and extinction," we focused on cranial remains because this element predominates among the later Pleistocene hominid remains from Java. In spite of the abundant fossil specimens, persistent limitations exist in the previous studies : analyses based on a small portion of the entire collection, and/or use of measurement data published by different researchers with varying methodologies. We observed and measured most of the existing cranial specimens from Java by ourselves, and constructed our own detailed measurement data set which is based on unified method. As a result, we found a series of significant morphological differences between the "early" (Trinil, Sangiran) and "later" (Ngandong) Javanese Homo erectus Furthermore, the three crania from Sambungmacan show largely intermediate morphological characteristics between the earlier and later groups. This supports the phylogenetic continuity in Java. At the same time, a number of morphological specializations seen in the Ngandong crania suggests discontinuity between Homo erectus and Homo sapiens populations in this region. Less