The stability of dinosaur communities before the Cretaceous–Paleogene (K–Pg) boundary: A perspective from southern Alberta using calcium isotopes as a dietary proxy

Abstract Reconstructing dinosaur trophic structure prior to the Cretaceous–Paleogene (K–Pg) boundary may provide information about ecosystem organization and evolution. Using calcium isotopes, we investigate preserved biogenic isotope compositions in a set of teeth from three continental formations Alberta, Canada, assess latest Cretaceous food web structure. Tooth enamel δ44/42Ca values are presented for tyrannosaurids (n = 34) potential large herbivorous prey 42) upper Campanian Dinosaur Provincial Park Formation, upper-most Campanian–Maastrichtian Horseshoe Canyon Maastrichtian–lower Paleocene Scollard spanning last ~10 m.y. Cretaceous. The influence diagenesis is assessed subset sample through major trace elemental concentrations ultraviolet (UV) Raman spectra, which provides framework interpreting values. In hadrosaurid systematically heavier than ceratopsid values, difference that interpreted reflect niche partitioning among megaherbivores. Tyrannosaurid scattered but on average, they 44Ca-depleted relative dinosaurs all formations. As data set, have preferentially fed hadrosaurids. These analyses offer possibilities testing whether non-avian ecosystems changed several millions years K–Pg boundary.