22-4 What Zooarchaeological Tooth Assemblages Can Tell Us About Paleoclimate: A Case Study From the Pleistocene-Holocene Transition in Mainland Southeast Asia

Session: Working Up an Apatite: Teeth as Paleo -Ecological and -Climatological Archives

Presenting Author:

Alliya Akhtar

Authors:

Akhtar, Alliya¹, Conrad, Cyler², Griffiths, Michael³, Szostak, Stella⁴, Gaitan, Adriana⁵, Higgins, John⁶, Niespolo, Elizabeth⁷

(1) Princeton University, Princeton, USA, (2) Pacific Northwest National Lab, Richland, USA, (3) William Paterson University, Wayne, USA, (4) Princeton University, Princeton, USA, (5) Princeton University, Princeton, USA, (6) Princeton University, Princeton, USA, (7) Princeton University, Princeton, USA,

Abstract:

Reconstructions of diet and trophic structures in ancient food webs often focus on geochemical analysis of teeth. The utility of this archive in reconstructing food web dynamics is based on observations of systematic shifts in isotopic or elemental concentration values of mineralized tissues across food chains. Here, we interrogate the fidelity of teeth as a geochemical archive, especially in light of the development of novel isotope (e.g., δ^44/40Ca, δ⁶⁶Zn, etc.) and (trace and rare-earth) elemental concentrations interpreted as paleoecological proxies.  We present data from in situ experiments modeling diffusive uptake of rare and trace elements (including U, Th, Zn, La, etc.) into teeth (including human and shark), tracking the rates of incorporation into enamel and dentin. 

We also present stable isotope (e.g., δ¹³C, δ¹⁸O, δ^44/40Ca) and trace element (e.g., Sr/Ca, Ba/Ca) data from modern and zooarchaeological mammalian tooth assemblages (including bamboo rats, macaques, wild boar, wild cattle and water buffalo) from northern Thailand. Our fossil results span the interval from 1 ka to 10 ka. Across all studied species, δ¹³C values range from -0.1 to -17.7‰, and δ^44/40Ca range from -2.0 to -4.2‰, indicating changes in consumption of C₃ and C₄ plants, as well as changes in canopy height foraging and/or habitat preferences. δ¹⁸O values (-0.6 to -12.1‰) provide insight on changes in precipitation. While intra- and inter- species nuances to the geochemical records exist, these results broadly agree with other proxy records that point to increases in canopy growth, regional temperature, and precipitation rates. We integrate our faunal dataset with other local records, including speleothem calcium isotope-derived semi-quantitative estimates of precipitation and regional paleoclimate reconstructions. 

 

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-11139

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.