An assessment of the nasal floor configurations of the available and sufficiently intact, archaic Homo maxillae from eastern Eurasia shows them to have a prevalence of the bi-level pattern similar to that seen in the western Eurasian Neanderthals.
A feature of Eurasian Homo skulls has been a bi-level nasal floor, although present in most Pleistocene and recent human samples, reaches its highest frequency among the western Eurasian Neanderthals and has been considered a feature distinctive of them. Early modern humans, in contrast, tend to feature a level (or sloping) nasal floor.
Internal nasal floor depression in Neanderthals
“Sufficiently intact maxillae are rare among eastern Eurasian Pleistocene humans, but several fossils provide nasal floor configurations”, said WU Xiujie of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), first author of the new study recently published in Anthropological Science, “Of the four observable eastern Eurasian archaic Homo maxillae, three have the bi-level pattern and the fourth is scored as bi-level/sloping. It therefore appears that bi-level nasal floors were common among Pleistocene archaic humans, and a high frequency of them is not distinctive of the Neanderthals”.
The dominance of bi-level and sloping nasal floors among the earlier, eastern Eurasian archaic human specimens could reflect unusual sampling of archaic populations possessing similar distributions of level and sloping configurations as seen in recent modern humans.
However, the taphonomic probability of exclusively recovering specimens with inferiorly displaced nasal floors from populations characterized by a preponderance of level configurations is small and statistically unlikely.
“If these eastern Eurasian archaic specimens are in fact representative of populations principally characterized by depressed nasal floors, then the dominance of the bi-level (and sloping) nasal floors in eastern Eurasian archaic humans would parallel that present in the (much larger) sample of Neandertals”, said co-author Scott Maddux, Department of Pathology and Anatomical Sciences, University of Missouri, Columbia.
The configurations of these eastern archaic maxillae, however, need not imply close affinities to the western Eurasian Neanderthals.
Superior views of the Sangiran 4, Chaoxian 1, Xujiayao 1, and Changyang 1 maxillae. All are oriented perpendicular to the midsagittalplane. Note than most of the Chaoxian 1 specimen has been reconstructed in plaster, based on the preserved palatal region. Credit: WU Xiujie
For example, several features of the nasomaxillary region have been shown to scale allometrically with overall facial size, both in recent humans and across Homo. A
Accordingly, the prevalence of depressed nasal floors in these two archaic Eurasian samples may simply be related to by both populations possessing similarly sized (large) faces, as nasal floor morphology is correlated with several measures of facial size across Homo, especially facial height and width.
“The relationships between nasal floor morphology and other aspects of facial size and shape remain uncertain, and they are difficult to evaluate with the available and incomplete eastern Eurasian remains. However, these results are sufficient to question whether a high frequency of the bi-level pattern is a distinctive Neanderthal feature and to query the phylogenetic and functional significance of this configuration”, said Erik Trinkaus, Department of Anthropology, Washington University, St Louis.
Thus, it appears reasonable to suggest that the prevalence of bi-level nasal floors in archaic eastern Eurasian humans existed in conjunction with relatively large facial dimensions. Moreover, the Chinese Middle Pleistocene specimen from Jinnuishan, which was not available for inclusion in this study, possesses both a relatively intact midface and nasal floor (Wu, 1988). Thus, future evaluation of the nasal floor in this fossil specimen may shed further light on the relationship between nasal floor morphology and facial size.
Source: Institute of Vertebrate Paleontology and Paleoanthropology / Anthropological Science
More Information
- Wu X, Maddux S, Pan L, Trinkaus E 2012 Nasal floor variation among eastern Eurasian Pleistocene Homo. Anthropol Sci, 2012 Full article
- Fabrice Demeter, Laura L. Shackelford, Anne-Marie Bacon, Philippe Duringer, Kira Westaway, Thongsa Sayavongkhamdy, José Braga, Phonephanh Sichanthongtip, Phimmasaeng Khamdalavong, Jean-Luc Ponche, Hong Wang, Craig Lundstrom, Elise Patole-Edoumba, and Anne-Marie Karpoff.2012 Anatomically modern human in Southeast Asia (Laos) by 46 ka. Proceedings of the National Academy of Sciences, August 20, 2012 DOI: 10.1073/pnas.1208104109 Full Article
- Curnoe D, Xueping J, Herries AIR, Kanning B, Taçon PSC, et al. 2012 Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians. PLoS ONE 7(3): e31918. doi:10.1371/journal.pone.0031918 Full Article
- Robert G Franciscus, 2003, Internal nasal floor configuration in Homo with special reference to the evolution of Neandertal facial form, Journal of Human Evolution Volume 44, Issue 6, June 2003, Pages 701–729 Full Article
