The variability of frontal and occipital features of Homo erectus: a comparative analysis of unpublished fragmentary fossils from Sangiran, Indonesia

Abstract

Since the first publication of Dubois in 1894, the diagnosis of Homo erectus is based on a list of morphological features established and updated after successive major discoveries made in the 20th century. While the existence and limits of the Homo erectus s.l is still debated, the homogeneity of the Indonesian Homo erectus, which covers a chronological period of ca. 1.5 million years, is also regularly questioned. Most of the studies addressing this question remain focused on the few most preserved specimens, even if a significant number of fragmentary specimens are available which could help to better appreciate the morphological variability of this species. In this present analysis, several unpublished fragmentary frontal (n=6) and occipital (n=9) bones recovered from the Pucangan and Kabuh layers in the Sangiran dome (Central Java) are described, analyzed and compared to the 3D models of contemporaneous (Trinil, Sangiran) and younger (Solo series) Indonesian H. erectus, specimens from Zhoukoudian Lower Cave in China, Dmanisi (Georgia), as well as East African hominins (East and West Turkana, Olduvai). The results help to precise the anatomical characteristics of these isolated human remains and increase our knowledge of Javanese Homo erectus morphological variability.