Natural Science Forum / Biology / Paleontology / December 2006

Nature 444, 748-751 (7 December 2006) | doi:10.1038/nature05314; Received 20 July 2006; Accepted 3 October 2006; Published online 22 November 2006

How Neanderthal molar teeth grew
Roberto Macchiarelli1, Luca Bondioli2, André Debénath3, Arnaud Mazurier1,4, Jean-François Tournepiche5,6, Wendy Birch7 and M. Christopher Dean7

 1.. Laboratoire de Géobiologie, Biochronologie et Paléontologie Humaine, UMR 6046 CNRS, Université de Poitiers, 86022 Poitiers, France
 2.. Sezione di Antropologia, Museo Nazionale Preistorico Etnografico 'L. Pigorini', 00144 Rome, Italy
 3.. Université de Perpignan, 66000 Perpignan, France
 4.. Etudes Recherches Matériaux, 86022 Poitiers, France
 5.. Musée d'Angoulême, 16000 Angoulême, France
 6.. UMR 5199 CNRS, Université Bordeaux 1, 33405 Bordeaux, France
 7.. Department of Anatomy and Developmental Biology, University College London, London WC1E 6BT, UK
Correspondence to: Correspondence and requests for materials should be addressed to C.D. (Email: ucgacrd@ucl.ac.uk).

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.

Source: Nature
http://www.nature.com/nature/journal/v444/n7120/abs/nature05314.html

Posted by
Robert Karl Stonjek