title: How Neanderthal molar teeth grew.
abstract: 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.
authors.affiliation: Laboratoire de Géobiologie, Biochronologie et Paléontologie Humaine, UMR 6046 CNRS, Université de Poitiers, 86022 Poitiers, France.
authors.forename: Roberto
authors.initials: R
authors.lastname: Macchiarelli
authors.forename: Luca
authors.initials: L
authors.lastname: Bondioli
authors.forename: André
authors.initials: A
authors.lastname: Debénath
authors.forename: Arnaud
authors.initials: A
authors.lastname: Mazurier
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Tournepiche
authors.forename: Wendy
authors.initials: W
authors.lastname: Birch
authors.forename: M Christopher
authors.initials: MC
authors.lastname: Dean
mesh_terms: 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