Subocclusal dental morphology of sahelanthropus tchadensis and the evolution of teeth in hominins.
The evolution of the teeth in hominins is characterized by, among other characters, major changes in root morphology. However, little is known of the evolution from a plesiomorphic, ape-like root morphology to the crown hominin morphology. Here we present a study of the root morphology of the Miocene Chadian hominin Sahelanthropus tchadensis and its comparison to other hominins. The morphology of the whole lower dentition (I1 -M3 ) was investigated and described. The comparison with the species Ardipithecus kaddaba and Ardipithecus ramidus indicates a global homogeneity of root morphology in early hominins. This morphology, characterized notably by a reduction of the size and number of the roots of premolars, is a composite between an ape-like morphology and the later hominin morphology. Trends for root evolution in hominins are proposed, including the transition from a basal hominoid to extant Homo sapiens. This study also illustrates the low association between the evolution of tooth root morphology and the evolution of crowns in hominins.
Collège de France, Chaire de Paléontologie Humaine, 3, rue d'Ulm, 75005, Paris, France; Institut international de Paléoprimatologie, Paléontologie Humaine: Evolution et Paléoenvironnements, UMR-CNRS 6046, faculté des Sciences, Université de Poitiers, 40 avenue du recteur Pineau, 86022, Poitiers, France.
Edouard-Georges
EG
Emonet
Likius
L
Andossa
Hassane
H
Taïsso Mackaye
Michel
M
Brunet
D000818:Animals; D000885:Anthropology, Physical; D005075:Biological Evolution; D005580:Fossils; D015186:Hominidae / Q000033:anatomy & histology*; D014070:Tooth / Q000033:anatomy & histology*; D019228:Tooth Crown / Q000033:anatomy & histology; D014092:Tooth Root / Q000033:anatomy & histology
Chad; dental roots; early hominins; root morphology; teeth evolution