The Neandertal lower right deciduous second molar from Trou de l'Abîme at Couvin, Belgium

Abstract

a b s t r a c tA human lower right deciduous second molar was discovered in 1984 at the entrance of Trou de l'Abîme at Couvin (Belgium). In subsequent years the interpretation of this fossil remained difficult for various reasons: (1) the lack of taxonomically diagnostic elements which would support its attribution to either Homo (sapiens) neanderthalensis or H. s. sapiens; (2) the absence of any reliable chronostratigraphic interpretation of the sedimentary sequence of the site; (3) the contradiction between archaeological interpretations, which attributed the lithic industry to a transitional facies between the Middle and Early Upper Palaeolithic, and the radiocarbon date of 46,820 AE 3,290 BP obtained from animal bone remains associated with the tooth and the flint tools.Thanks to recent progress regarding these three aspects, the tooth from Trou de l'Abîme may now be studied in detail. Analyses of the morphology and enamel thickness of the fossil yielded diagnostic characters consistent with an attribution to Neandertals. Re-examination of the lithic industry of Couvin shows that it corresponds to the late Middle Palaeolithic rather than a transitional facies. Furthermore, a new analysis of the site stratigraphy indicates that the unit situated above the archaeological layer in which the tooth was found is probably a palaeosol of brown soil type. Comparison with the regional cave sequences as well as with the reference sequence from the Belgian loess belt tends to show that the most recent palaeosol of this type is dated between 42,000 and 40,000 BP. This is consistent with both a recently obtained AMS result at 44,500 BP and the published conventional date.

Postnatal craniofacial ontogeny in neandertals and modern humans

“…Interest in Neandertal postnatal ontogeny accelerated when Engis 2 was recognized as belonging to this fossil taxon (Fraipont, 1936;Tillier, 1983). Additional infants, juveniles and subadults have been documented and examined (Martin, 1926;Garrod et al, 1928; Fraipont, 1936;Smith, 1976;Skinner, 1978; Smith and Raynard, 1980;Heim, 1982;Tillier, 1982Tillier, , 1983Tillier, , 1987Tillier, , 1989Minugh-Purvis, 1988;Akazawa et al, 1995;Dodo et al, 1998;Tompkins, 1996;Minugh-Purvis et al, 2000;Arsuaga et al, 2007;David et al, 2009;Glantz et al, 2009;Toussaint et al, 2010). Traits typical of adults have been noted in Neandertal immatures by several researchers (Martin, 1926;Garrod et al, 1928; Fraipont, 1936;Heim, 1982;Tillier, 1982Tillier, , 1983Akazawa et al, 1995;Dodo et al, 1998;Maureille, 2002;David et al, 2009;Toussaint et al, 2010), although immature remains were smaller than expected, reflected in strong positive allometries of the craniofacial region (Williams, 2000).…”

Is the deciduous/permanent molar enamel thickness ratio a taxon-specific indicator in extant and extinct hominids?

“…To quantify lateral enamel, the bestfit plane across the cervicoenamel line was firstly set on each crown and the tooth material below this basal plane eliminated (Olejniczak et al, 2008a). Then, a parallel plane to the former, tangent to the lowest enamel point of the occlusal basin, was defined and all material above it was also removed (Macchiarelli et al, 2013;Toussaint et al, 2010). Only the enamel and dentine portions between these two planes was preserved to estimate tissue proportions.…”

Comparison of maxillary first molar occlusal outlines of Neandertals from the Meuse River Basin of Belgium using elliptical Fourier analysis

“…Radiocarbon dates of 26,830 ± 430 and 30,460 ± 210 years BP from the parietal bone are believed to be too recent, and do not accord with the artifact assemblage (Toussaint and Pirson 2006;Toussaint et al 2011;Di Modica et al 2016). Engis 2 includes a calvarium and an isolated maxillary fragment of a child aged 4-5 years (Tillier 1983;Toussaint and Pirson 2006;Williams 2013), and is associated with an unworn, probably unerupted, right maxillary permanent first molar ( Fig. 1) with slightly less than 1 mm of root development.…”

“…The taphonomic context of Engis 2 is poorly known owing to its discovery in the winter of 1829-1830, prior to the development of precise excavation techniques (Twiesselmann 1971;Semal et al 2013;Toussaint and Pirson 2006;Toussiant et al 2011). Radiocarbon dates of 26,830 ± 430 and 30,460 ± 210 years BP from the parietal bone are believed to be too recent, and do not accord with the artifact assemblage (Toussaint and Pirson 2006;Toussaint et al 2011;Di Modica et al 2016).…”

“…The taphonomic context of Engis 2 is poorly known owing to its discovery in the winter of 1829-1830, prior to the development of precise excavation techniques (Twiesselmann 1971;Semal et al 2013;Toussaint and Pirson 2006;Toussiant et al 2011). Radiocarbon dates of 26,830 ± 430 and 30,460 ± 210 years BP from the parietal bone are believed to be too recent, and do not accord with the artifact assemblage (Toussaint and Pirson 2006;Toussaint et al 2011;Di Modica et al 2016). Engis 2 includes a calvarium and an isolated maxillary fragment of a child aged 4-5 years (Tillier 1983;Toussaint and Pirson 2006;Williams 2013), and is associated with an unworn, probably unerupted, right maxillary permanent first molar ( Fig.…”