Oxygen isotope variation in the tusks of extinct proboscideans: A measure of season of death and seasonality

Research Article| June 01, 1989 Oxygen isotope variation in the tusks of extinct proboscideans: A measure of season of death and seasonality Paul L. Koch; Paul L. Koch 1Department of Geological Sciences and Museum of Paleontology, University of Michigan, Ann Arbor, Michigan 48109 Search for other works by this author on: GSW Google Scholar Daniel C. Fisher; Daniel C. Fisher 1Department of Geological Sciences and Museum of Paleontology, University of Michigan, Ann Arbor, Michigan 48109 Search for other works by this author on: GSW Google Scholar David Dettman David Dettman 2Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109 Search for other works by this author on: GSW Google Scholar Geology (1989) 17 (6): 515–519. https://doi.org/10.1130/0091-7613(1989)017<0515:OIVITT>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Paul L. Koch, Daniel C. Fisher, David Dettman; Oxygen isotope variation in the tusks of extinct proboscideans: A measure of season of death and seasonality. Geology 1989;; 17 (6): 515–519. doi: https://doi.org/10.1130/0091-7613(1989)017<0515:OIVITT>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Centimetre-scale laminae in tusk and molar dentine of late Pleistocene mastodonts and mammoths have been interpreted as annual growth bands produced, in part, by seasonal variation in growth rate. To test this interpretation, we measured the oxygen isotope composition (δ18O) of the CO3 fraction of dentinal hydroxyapatite from samples covering consecutive inferred years of growth in tusks. In mammals, changes in the δ18O value of dental tissues within individuals predominantly reflect variation in the δ18O value of body fluids, which is controlled mainly by the isotopic composition of ingested water. In Northern Hemisphere continental regions, winter precipitation has substantially lower δ18O values than does precipitation in other seasons. If ingested water tracks focal precipitation, then seasonal variations in dentinal isotope composition should result, the lowest δ18O values representing winter growth. We demonstrate that there are substantial variations in the oxygen isotope composition of proboscidean dentinal apatite, and that isotopic identifications of winter (i.e., low δ18O values) coincide with those based on growth rate (i.e., slow-growth zones). Finally, the potential of oxygen isotope analyses of terrestrial mammals for assessing the seasonality of paleoclimates is considered. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.