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

A new study using calcium isotopes reveals that dinosaur communities in southern Alberta exhibited stable trophic structures before the Cretaceous–Paleogene (K–Pg) boundary. Analysis of tooth enamel from tyrannosaurids and herbivorous dinosaurs across three formations—Dinosaur Provincial Park, Horseshoe Canyon, and Scollard—shows distinct isotopic differences between hadrosaurids and ceratopsids, suggesting niche partitioning among megaherbivores. Tyrannosaurid δ44/42Ca values indicate they likely fed preferentially on hadrosaurids. These findings hint at long-term stability in dinosaur food webs, offering potential insights into ecosystem dynamics prior to the K–Pg extinction event.

Martin, J. E., Hassler, A., Montagnac, G., Therrien, F., & Balter, V. (2022). The stability of dinosaur communities before the Cretaceous–Paleogene (K–Pg) boundary: A perspective from southern Alberta using calcium isotopes as a dietary proxy. GSA Bulletin, 134(9-10), 2548–2560. https://doi.org/10.1130/b36222.1