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，我们重点对相对丰富的下颌和牙齿材料进行了形态分析。最古老的爪哇原始人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“可比得上南方古猿”到“可比得上周口店直立人”，缺乏对现有化石材料的全面、系统的比较分析，可能是造成这种困惑的主要原因之一。因此，我们调查了现有的大部分化石材料，考虑到了这些化石的最新年代学信息。这一结果表明了一种介于上述两种极端观点之间的观点：最古老的爪哇原始人与来自肯尼亚和其他地区的非洲早期直立人最相似。同时，我们的分析表明，桑吉兰原始人并不是同源的，而是两个形态上截然不同的…关于“进化和灭绝”，我们把重点放在头骨遗骸上，因为这一元素在爪哇更新世晚期的原始人遗骸中占主导地位。尽管有丰富的化石标本，但以前的研究存在持久的局限性：基于整个集合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布的测量数据。我们自行观察和测量了大部分现有的爪哇颅骨标本，并构建了自己的详细测量数据集，该数据集基于统一的方法。结果，我们发现了“早期”爪哇直立人和“晚期”爪哇直立人之间的一系列显著的形态差异。此外，Sambungmacan的三个头骨在早期和晚期群体之间表现出很大程度的中间形态特征。这支持了Java的系统发育连续性。同时，在安东头盖骨中发现的一些形态特化表明，该地区直立人和智人种群之间的不连续。较少

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