Additional Evidence for Morpho-Dimensional Tooth Crown Variation in a New Indonesian H. erectus Sample from the Sangiran Dome (Central Java)

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.

Descriptions of the dental remains of <i>Homo floresiensis</i>

“…This morphology is also rare among the MiddleLate Pleistocene European archaic Homo (Martinón-Torres et al, 2012). However, Zanolli (2013) recently reported four four-cusped M 2 s that may have been derived from the terminal Early Pleistocene Bapang (Kabuh) Formation in the Sangiran Dome, Central Java (chronology based on Hyodo et al, 2011). Four-cusped M 2 s are relatively common in modern human populations (24%), but four-cusped M 1 s are rare (1%) (calculated from the data based on a large global modern human sample (n = 6790-8638) in Scott and Turner, 1997: Appendix A).…”

Age estimation in fossil hominins: comparing dental development in earlyHomowith modern humans

“…The specimen is adult and was recovered from the Pucangan formation of the Sangiran Dome, Java, Indonesia, along with many other fossil hominins during a 5-year period from 1937-1941 by G. H. R. von Koenigswald (Grine & Franzen, 1994). S7-37 has been placed in the time span between 0.7-1.3 million years (Grine & Franzen, 1994); but see a recent discussion about the dating of these hominins in Zanolli (2013). Dean et al (2001) made histological sections of the crowns and roots of both the M 1 and P 4 of S7-37.…”

Neutron Imaging in Cultural Heritage Research at the FRM II Reactor of the Heinz Maier-Leibnitz Center

“…The outer surface of even slightly worn teeth does not give sufficient information for diagnostic discrimination ( Figure 5) [9], but the interface between enamel and dentine is different for both species. Human teeth have higher relief of the dentine whereas it is more flat and squat in orangutans [10].…”

“…The photo of the H. erectus molar is from [9] (open access), whereas all other illustrations are original pictures. tissues, depending on the geological environment.…”

“…The photo of the H. erectus molar is from [9] (open access), whereas all other illustrations are original pictures. In mandibular specimens (a), due to fossilization, we sometimes obtained noisy datasets (b), but it was still possible to retrieve reliable morphological information on the internal tooth structure (c) [11] (with permission).…”