title: Carbon isotope fractionation between diet and bioapatite in ungulate mammals and implications for ecological and paleoecological studies.
abstract: The isotope enrichment ɛ* of13C between tooth enamel of large ruminant mammals and their diet is 14.1 ± 0.5‰. This value was obtained by analyzing both the dental enamel of a variety of wild and captive mammals and the vegetation that comprised their foodstuffs. This isotope enrichment factor applies to a wide variety of ruminant mammals. Non-ruminant ungulates have a similar isotope enrichment, although our data cannot determine if it is significantly different. We also found a13C isotope enrichment ɛ* of 3.1 ± 0.7‰ for horn relative to diet, and 11.1 ± 0.8‰ for enamel relative to horn for ruminant mammals. Tooth enamel is a faithful recorder of diet. Its isotopic composition can be used to track changes in the isotopic composition of the atmosphere, determine the fraction of C3or C4biomass in diets of modern or fossil mammals, distinguish between mammals using different subpathways of C4photosynthesis,and identify those mammals whose diet is derived from closed-canopy habitats.
authors.affiliation: Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA e-mail: tcerling@bingham.mines.utah.edu, Fax: +1-801-5817065, , , , , , US.
authors.forename: Thure E
authors.initials: TE
authors.lastname: Cerling
authors.affiliation: The George C. Page Museum, 5801 Wilshire Boulevard, Los Angeles, CA 90036, USA, , , , , , US.
authors.forename: John M
authors.initials: JM
authors.lastname: Harris
keywords: Carbon isotopes; Diet; Enamel; Key words Isotope fractionation