Magnesium stable isotope ecology using mammal tooth enamel

Area of Science:

• Paleoecology
• Geochemistry
• Isotope analysis

Background:

• Traditional paleodietary proxies like carbon isotopes (δ(13)C) have limitations.
• Nontraditional stable isotopes offer new avenues for reconstructing complex diets.

Purpose of the Study:

• To investigate the utility of stable magnesium isotopes (δ(26)Mg) as a paleodietary proxy.
• To assess the relationship between δ(26)Mg in tooth enamel and an animal's trophic level.

Main Methods:

• Analysis of tooth enamel, vegetation, and feces from 11 extant African mammal species.
• Measurement of δ(26)Mg, δ(13)C, Sr/Ca, and Ba/Ca ratios.

Main Results:

• Tooth enamel δ(26)Mg values increase from herbivores to omnivores/faunivores.
• A potential mechanism for this enrichment is increased δ(26)Mg in muscle tissue.
• δ(26)Mg combined with Ba/Ca ratios can differentiate herbivores from omnivores.

Conclusions:

• Stable magnesium isotopes show promise for paleodietary reconstruction, particularly for distinguishing feeding strategies.
• Multiproxy approaches incorporating δ(26)Mg can refine our understanding of ancient trophic ecology.