How Neanderthal molar teeth grew.
Growth and development are both fundamental components of demographic structure and life history strategy. Together with information about developmental timing they ultimately contribute to a better understanding of Neanderthal extinction. Primate molar tooth development tracks the pace of life history evolution most closely, and tooth histology reveals a record of birth as well as the timing of crown and root growth. High-resolution micro-computed tomography now allows us to image complex structures and uncover subtle differences in adult tooth morphology that are determined early in embryonic development. Here we show that the timing of molar crown and root completion in Neanderthals matches those known for modern humans but that a more complex enamel-dentine junction morphology and a late peak in root extension rate sets them apart. Previous predictions about Neanderthal growth, based only on anterior tooth surfaces, were necessarily speculative. These data are the first on internal molar microstructure; they firmly place key Neanderthal life history variables within those known for modern humans.
Macchiarelli
Roberto
R
Laboratoire de Géobiologie, Biochronologie et Paléontologie Humaine, UMR 6046 CNRS, Université de Poitiers, 86022 Poitiers, France.
Bondioli
Luca
L
Debénath
André
A
Mazurier
Arnaud
A
Tournepiche
Jean-François
JF
Birch
Wendy
W
Dean
M Christopher
MC
D000818:Animals; D003743:Dental Enamel / Q000254:growth & development; D005260:Female; D005580:Fossils; D049690:History, Ancient; D015186:Hominidae / Q000502:physiology*; D006801:Humans; D008297:Male; D008963:Molar / Q000254:growth & development*; D013997:Time Factors