Life and reproduction of titanosaurians: Isotopic hallmark of mid-palaeolatitude eggshells and its significance for body temperature, diet, and nesting

Eggshells represent an important part of the fossil record Titanosauria (Dinosauria – Neosauropoda) and their stable isotope compositions are valuable palaeoenvironmental proxies. A new set conventional (δ18O δ13C) clumped (Δ47) titanosaurian eggshells is presented, together with that a bone single associated tooth, sampled in three Late Cretaceous nesting sites from La Rioja Province, NW Argentina. The preservation state fossils was first evaluated using optical analytical techniques, such as transmitted light cathodoluminescence (CL) microscopy, energy dispersive X-ray spectroscopy (EDX), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). isotopic were then compared to those carbonate rocks nodules, hydrothermal calcite quartz, reported for other worldwide. This large, combined sample allows us define hallmark (δ13CVPDB = −15 −11‰; δ18OVSMOW 27 33‰) typical well-preserved mid-palaeolatitude eggshells. intended identify oological specimens best suited reconstructions, instance museum collection samples may lack abiogenic materials host rocks. In addition, our data support titanosaurians animals elevated body temperature, mainly feeding on C3 plants, reproducing under conditions more arid than long-term average. excellent agreement around world, indicating needed similar environmental reproduce, regardless palaeogeographic location habitat. Finally, we raise question whether experienced reproduction-related fasting, noted several extant vertebrates, discuss complexity interpreting Δ47-derived temperatures, despite very consistent bulk data.