Additional evidence for morpho-dimensional tooth crown variation in a New Indonesian H. erectus sample from the Sangiran Dome (Central Java)

PLoS One. 2013 Jul 3;8(7):e67233. doi: 10.1371/journal.pone.0067233. Print 2013.

Abstract

This contribution reports fifteen human fossil dental remains found during the last two decades in the Sangiran Dome area, in Central Java, Indonesia. Among this sample, only one of the specimens had already been briefly described, with the other fourteen remaining unreported. Seven of the fifteen isolated teeth were found in a secured stratigraphic context in the late Lower-early Middle Pleistocene Kabuh Formation. The remaining elements were surface finds which, based on coincidental sources of information, were inferred as coming from the Kabuh Formation. Mainly constituted of permanent molars, but also including one upper incisor and one upper premolar, this dental sample brings additional evidence for a marked degree of size variation and time-related structural reduction in Javanese H. erectus. This is notably expressed by a significant decrease of the mesiodistal diameter, frequently associated to the reduction or even loss of the lower molar distal cusp (hypoconulid) and to a more square occlusal outline. In addition to the hypoconulid reduction or loss, this new sample also exhibits a low frequency of the occlusal Y-groove pattern, with a dominance of the X and, to a lesser extent, of the+patterns. This combination is rare in the Lower and early Middle Pleistocene paleoanthropological record, including in the early Javanese dental assemblage from the Sangiran Dome. On the other hand, similar dental features are found in Chinese H. erectus and in H. heidelbergensis. As a whole, this new record confirms the complex nature of the intermittent exchanges that occurred between continental and insular Southeast Asia through the Pleistocene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fossils*
  • Geography
  • Humans
  • Indonesia
  • Paleodontology
  • Tooth Crown / anatomy & histology*

Grants and funding

This PhD research program was not accompanied by a specific grant covering the three years work. However, during that period the author benefited in 2009 of a Deutscher Akademischer Austauschdienst Dienst grant (total amount of 3,200 euro) to spend three months at the Senckenberg Museum in Frankfurt in order to comparatively examine the locally stored Indonesian fossil hominid dental material, and, in 2011, of the André Leroi-Gourhan grant (1,500 euro), provided by the Société des Amis du Musée de l’Homme as contribution to the microtomographic analysis of orangutan dental material stored at the Senckenberg Museum and to participate the 15th International Symposium on Dental Morphology held the same year in Newcastle. In any case, these two grants had only poor direct impact on the study design, data collection and analysis, decision to publish, or preparation of the manuscript submitted to PLOS.