Post by Admin on Dec 14, 2020 6:41:40 GMT
Palatine torus
Palatine torus is defined as a bony exostosis occurring on the median palatine suture [35, 36]. In the Altamura Neanderthal, this feature is well marked (Fig 8) and can be scored at least as a grade 3 torus, following [36]. Table 2 lists the Paleolithic Homo specimens where the palatine torus has been observed [9, 35, 37–39]. Most of them are assigned to Homo sapiens; however, a torus has also been reported in the partial cranium D2282 from Dmanisi [9] and in the Middle Pleistocene hominin skull Kabwe 1 [39]. Among Neanderthals, palatine torus has been reported only for Guattari 1, the Neanderthal skull from Monte Circeo [35, 38] (but see [40]).
Fig 8. Palatine torus.
View of the maxillary dental arch and palate. The well-marked bony exostosis on the median palatine suture of the Altamura Neanderthal can be scored as a grade 3 torus [36]. This is the first well-documented case of palatine torus in Neanderthals.
However, in some of the listed cases (Isturitz, Mladec 1, Mladec palate #5487), the authors are not sure of the presence of the torus, whereas in some others (Kabwe 1, Guattari 1) they may refer to something different from palatine torus sensu stricto as defined in [36]. Indeed, in the Kabwe 1 skull, the torus is described as “divided, with central sulcus” ([39], p.110), although Scott and Irish [36] exclude this kind of bony exostosis from the definition of palatine torus. In the case of Guattari 1, the situation is not straightforward. In their analysis of cranial epigenetic traits in the Neanderthal sample, Manzi et al. [40] comment that “The superficial osseous layer of the hard palate is destroyed and the area involved does not permit the usual scoring of a palatine torus; however, according to Sergi et al. (1934), the spongy substance visible along the midline could indicate the presence of a well developed palatine torus.” Following his original observations, Sergi himself described a very irregular palatal surface characterized by “many knobby and transversally oriented, elongated protrusions” ([38], p. 189). Direct observation of the Guattari 1 cranium by one of the present authors (AR) suggests the absence of a palatine torus as defined in [36].
Taurodontism
Taurodontism, i.e. enlargement of the pulp chamber with a concomitant apical shift of the root furcation, is a feature also described in Homo sapiens but usually occurring with high frequency in the posterior dentition of Neanderthals [41–44]. Some authors have suggested that this trait could be an adaptation to high masticatory loads [43], but a more recent study argued that the relationship between masticatory biomechanics and an enlarged pulp chamber is weak and thus taurodontism is likely the result of genetic drift or other non-adaptive evolutionary mechanisms [44]. In the Altamura specimen, exposure of the molar roots allows some observations on this trait. In RM1, the position of the root furcation can be estimated at about half of the total tooth height (Fig 5); this condition can thus be classified as hypotaurodont, following [20]. In the other molars, despite the marked exposure of the roots, no root furcation is evident; in the maxillary molars, this could be linked to the thick calcite layer covering the roots and thus preventing any observation, whereas in the mandibular molars, where the calcite layer is thinner and the root surface visible, it probably suggests that they are characterized by weak taurodontism as well.
Palatine torus is defined as a bony exostosis occurring on the median palatine suture [35, 36]. In the Altamura Neanderthal, this feature is well marked (Fig 8) and can be scored at least as a grade 3 torus, following [36]. Table 2 lists the Paleolithic Homo specimens where the palatine torus has been observed [9, 35, 37–39]. Most of them are assigned to Homo sapiens; however, a torus has also been reported in the partial cranium D2282 from Dmanisi [9] and in the Middle Pleistocene hominin skull Kabwe 1 [39]. Among Neanderthals, palatine torus has been reported only for Guattari 1, the Neanderthal skull from Monte Circeo [35, 38] (but see [40]).
Fig 8. Palatine torus.
View of the maxillary dental arch and palate. The well-marked bony exostosis on the median palatine suture of the Altamura Neanderthal can be scored as a grade 3 torus [36]. This is the first well-documented case of palatine torus in Neanderthals.
However, in some of the listed cases (Isturitz, Mladec 1, Mladec palate #5487), the authors are not sure of the presence of the torus, whereas in some others (Kabwe 1, Guattari 1) they may refer to something different from palatine torus sensu stricto as defined in [36]. Indeed, in the Kabwe 1 skull, the torus is described as “divided, with central sulcus” ([39], p.110), although Scott and Irish [36] exclude this kind of bony exostosis from the definition of palatine torus. In the case of Guattari 1, the situation is not straightforward. In their analysis of cranial epigenetic traits in the Neanderthal sample, Manzi et al. [40] comment that “The superficial osseous layer of the hard palate is destroyed and the area involved does not permit the usual scoring of a palatine torus; however, according to Sergi et al. (1934), the spongy substance visible along the midline could indicate the presence of a well developed palatine torus.” Following his original observations, Sergi himself described a very irregular palatal surface characterized by “many knobby and transversally oriented, elongated protrusions” ([38], p. 189). Direct observation of the Guattari 1 cranium by one of the present authors (AR) suggests the absence of a palatine torus as defined in [36].
Taurodontism
Taurodontism, i.e. enlargement of the pulp chamber with a concomitant apical shift of the root furcation, is a feature also described in Homo sapiens but usually occurring with high frequency in the posterior dentition of Neanderthals [41–44]. Some authors have suggested that this trait could be an adaptation to high masticatory loads [43], but a more recent study argued that the relationship between masticatory biomechanics and an enlarged pulp chamber is weak and thus taurodontism is likely the result of genetic drift or other non-adaptive evolutionary mechanisms [44]. In the Altamura specimen, exposure of the molar roots allows some observations on this trait. In RM1, the position of the root furcation can be estimated at about half of the total tooth height (Fig 5); this condition can thus be classified as hypotaurodont, following [20]. In the other molars, despite the marked exposure of the roots, no root furcation is evident; in the maxillary molars, this could be linked to the thick calcite layer covering the roots and thus preventing any observation, whereas in the mandibular molars, where the calcite layer is thinner and the root surface visible, it probably suggests that they are characterized by weak taurodontism as well.