Stable isotopic studies of dinosaur eggshells from the Nanxiong Basin, South China

Stable carbon and oxygen isotopes have been observed in dinosaur eggshell samples, identified asMacroolithus yaotunensis, collected in two sections of the Nanxiong Basin, Guangdong Province, South China. Multiple positive δ18O perturbations that occurred during the K/T transition of about 150 ka suggest that there may have been at least three periods of the extreme dry climate with a mean annual air temperature over 27δC. δ13C ranges from -8.37% to -11.60% of the dinosaur eggshells, added to the metabolic enrichment of 16%, may indicate that the dinosaurs represented by this type of eggshells probably consumed the plant species of C3 type with the δ13C values of -24.3%— -27.6‰ Moreover, the trend toward more negative δ13C values of the eggshells during the K/T transition could be an indirect consequence of a lasting increase in atmospheric CO2 concentration.