Proportions (% absence) of the Hld and occlusal groove pattern occurrence in the new Javanese fossil human dental sample compared to the figures from eleven extant and fossil human samples.

a<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067233#pone.0067233-MartinnTorres1" target="_blank">[90]</a>,</p>b<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067233#pone.0067233-Grine2" target="_blank">[8]</a>,</p>c<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067233#pone.0067233-Kaifu2" target="_blank">[12]</a>,</p>d<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067233#pone.0067233-vonKoenigswald1" target="_blank">[2]</a>,</p>e<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067233#pone.0067233-Weidenreich2" target="_blank">[88]</a>.</p

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

<div><p>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 <i>H. erectus</i>. 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 <i>H. erectus</i> and in <i>H. heidelbergensis</i>. 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.</p></div

MD vs. BL diameter plots for the LM1 (A), LM2 (B) and LM3 crowns (C) from the new Javanese fossil human dental sample compared to the figures from thirteen extant and fossil human samples represented by 95% confident equiprobable ellipses.

<p>The specimens NG92.3, NG92.D6 ZE 57s/d 76 and NG0802.2 for which the serial attribution is uncertain appear in both LM2 and LM3 graphs.</p

Individual non-metric crown features and dimensions of the new Javanese fossil human dental sample.

<p>Individual non-metric crown features and dimensions of the new Javanese fossil human dental sample.</p

Cusp area estimates of eight LM2 and LM3 crowns from the new Javanese fossil human dental sample compared to the figures from six extant and fossil human specimens/samples.

<p>Into parentheses, the s.d.</p>a<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067233#pone.0067233-Wood2" target="_blank">[75]</a>,</p>b<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067233#pone.0067233-BermdezdeCastro1" target="_blank">[84]</a>,</p>c<p>original data.</p

Adjusted Z-score graphs of relative molar cusp area in NG92.1 (A), NG92.4 (B), NG0802.3 (C), PCG09_KII_Z1.37 (D), NG9107.2 (E), NG92.3 (F), NG92.D6 ZE 57s/d 76 (G), and NG0802.2 (H) from the new Javanese fossil human dental sample compared to the LM2 and/or LM3 figures from five extant and fossil human samples.

<p>The full line passing through the zero represents the mean and the dotted lines correspond to the estimated 95% limit of variation expressed for each group. Each symbol corresponds to a distinct cusp base area for the tested specimen.</p

Linear (MD and BL in mm), surface (CCA in mm²) and proportion estimates (CI in %) of ten lower molar crowns from the new Javanese fossil human dental sample compared to the figures from thirteen extant and fossil human specimens/samples.

<p>The estimates of three indeterminate specimens (NG92.3, NG92.D6 ZE 57s/d 76, NG0802.2) are duplicated into the LM2 and LM3 columns.</p

Neanderthal and Denisova tooth protein variants in present-day humans

<div><p>Environment parameters, diet and genetic factors interact to shape tooth morphostructure. In the human lineage, archaic and modern hominins show differences in dental traits, including enamel thickness, but variability also exists among living populations. Several polymorphisms, in particular in the non-collagenous extracellular matrix proteins of the tooth hard tissues, like enamelin, are involved in dental structure variation and defects and may be associated with dental disorders or susceptibility to caries. To gain insights into the relationships between tooth protein polymorphisms and dental structural morphology and defects, we searched for non-synonymous polymorphisms in tooth proteins from Neanderthal and Denisova hominins. The objective was to identify archaic-specific missense variants that may explain the dental morphostructural variability between extinct and modern humans, and to explore their putative impact on present-day dental phenotypes. Thirteen non-collagenous extracellular matrix proteins specific to hard dental tissues have been selected, searched in the publicly available sequence databases of Neanderthal and Denisova individuals and compared with modern human genome data. A total of 16 non-synonymous polymorphisms were identified in 6 proteins (ameloblastin, amelotin, cementum protein 1, dentin matrix acidic phosphoprotein 1, enamelin and matrix Gla protein). Most of them are encoded by dentin and enamel genes located on chromosome 4, previously reported to show signs of archaic introgression within Africa. Among the variants shared with modern humans, two are ancestral (common with apes) and one is the derived enamelin major variant, T648I (rs7671281), associated with a thinner enamel and specific to the <i>Homo</i> lineage. All the others are specific to Neanderthals and Denisova, and are found at a very low frequency in modern Africans or East and South Asians, suggesting that they may be related to particular dental traits or disease susceptibility in these populations. This modern regional distribution of archaic dental polymorphisms may reflect persistence of archaic variants in some populations and may contribute in part to the geographic dental variations described in modern humans.</p></div

Non-synonymous polymorphisms present in tooth proteins of Neanderthal and Denisova hominins.

<p>Non-synonymous polymorphisms present in tooth proteins of Neanderthal and Denisova hominins.</p

Localization of tooth protein genes in two clusters on chromosome 4.

<p>Localization of tooth protein genes in two clusters on chromosome 4.</p