The reconstruction of mammal individual history: refining high-resolution isotope record in bovine tooth dentine Antoine Zazzo a,b, * , Marie Balasse c , William P. Patterson a a Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK, Canada S7N 5E2 b CNRS UPR 2147 ‘‘Dynamique de l’Evolution humaine: Individus, Populations, Espe `ces’’, 44 rue de l’Amiral Mouchez, 75014 Paris, France c CNRS UMR 5197 ‘‘Arche ´ozoologie, Histoire des Socie ´te ´s humaines et des Peuplements animaux’’, Muse ´um national d’Histoire naturelle, De ´partement Ecologie et Gestion de la Biodiversite ´, 55 rue Buffon, 75231 Paris Cedex 05, France Received 29 September 2005; received in revised form 13 December 2005; accepted 20 December 2005 Abstract Longitudinal and transverse carbon isotope profiles were performed on tooth dentine from five steers (Bos taurus) initially fed C 3 and subsequently C 4 -dominant food. Comparison of different protocols for bioapatite extraction revealed that the use of NaOCl considerably reduced the amplitude of variation of d 13 C within a tooth. Increasing contribution of C 4 food to the carbon isotope composition of bioapatite was found from the tip of the tooth crown to the neck and from the enameledentine junction toward the pulp cavity. These findings confirm that the model of dentine growth as a succession of stacked cones applies to bovines. Temporal resolution is estimated to be 4 months in transverse profiles, significantly better than in longitudinal dentine profiles (8e9 months) or even in profiles derived from enamel of the same individual (6e 7 months). Temporal resolution could be improved by a factor of two by selecting a different sampling zone or refining our sampling protocol. This sampling strategy could also be applied to dentine collagen and has important ecological and archaeological implications including deter- mination of the season of weaning, or the reconstruction of mobility strategies. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Dentine; Stable isotopes; Dietary reconstruction; Mammal; Intra-tooth profiles 1. Introduction Research involving stable isotope analysis of vertebrate skeletal remains has lately focused on reconstruction of life history through sequential sampling of animal teeth. Investi- gating environmental variation and diet changes in wild and domestic animal life history at annual or subannual scale has served various applications in palaeoenvironmental and palaeoclimatological reconstruction (e.g. [17e19,25,26, 29,40,41,45,47]), biological and physiological investigation (timing of tooth development: [17,28,41]; investigation of weaning: [8,22]) and anthropological research essentially related to zooarchaeological perspectives [5,6,9e12,34]. Most of these studies have focused on the mineral fraction (bioapatite) of tooth enamel for several reasons. First, because of its larger, more tightly packed and highly organized apatite crystals, enamel is less susceptible to post-depositional isotope exchange or alteration than other less densely mineralized tissues such as bone and dentine [31e33,48]. Secondly, because its deposition as a single layer that is not remodeled once fully mineralized made it a good candidate for the re- cording of isotope signals over the period of tooth growth, spanning a year to a few decades. Lastly, enamel has been preferentially used because it forms the exterior coating of teeth, and therefore it is more easily reached with minimal de- struction of the specimen unlike dentine that forms the bulk of the tooth. * Corresponding author. Present address: School of Biology and Environ- mental Sciences, UCD Agriculture and Food Science Center, University College Dublin, Belfield, Dublin 4, Ireland. E-mail address: antoine.zazzo@usask.ca (A. Zazzo). 0305-4403/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.jas.2005.12.006 ARTICLE IN PRESS Journal of Archaeological Science xx (2006) 1e11 http://www.elsevier.com/locate/jas + MODEL