Calibrating the zenith of dinosaur diversity in the Campanian of the Western Interior Basin by CA-ID-TIMS U–Pb geochronology

A new high-resolution chronostratigraphic framework for the upper Campanian of the Western Interior Basin reveals significant age overlap between key fossil-bearing formations, spanning 1600 km from southern Alberta to northwest New Mexico. This finding challenges previous assumptions about faunal provinciality and supports a connection between paleoecologic and fossil diversities during the 'zenith of dinosaur diversity.' The study employed CA-ID-TIMS U-Pb geochronology on 16 bentonite beds, providing precise age constraints from 82.419 ± 0.074 Ma to 73.496 ± 0.039 Ma. These results offer a robust temporal basis for further paleontologic analyses and refine our understanding of dinosaur paleoecology and biogeography during this critical period.

Ramezani, J., Beveridge, T. L., Rogers, R. R., Eberth, D. A., & Roberts, E. M. (2022). Calibrating the zenith of dinosaur diversity in the Campanian of the Western Interior Basin by CA-ID-TIMS U–Pb geochronology. Scientific Reports, 12(1). https://doi.org/10.1038/s41598-022-19896-w