Abstract
The Late Cretaceous of Western North America (Laramidia) supported a diverse dinosaur fauna, with duckbilled dinosaurs (Hadrosauridae) being among the most speciose and abundant members of this assemblage. Historically, collecting and preservational biases have meant that dinosaurs from Mexico and the American Southwest are poorly known compared to those of the northern Great Plains. However, evidence increasingly suggests that distinct species and clades inhabited southern Laramidia. Here, a new kritosaurin hadrosaurid, represented by the anterior part of a skull, is reported from the late Campanian of the Cerro del Pueblo Formation, ~72.5 Ma, in Coahuila, Mexico. The Cerro del Pueblo Formation kritosaur was originally considered to represent the same species as a saurolophine from the Olmos Formation of Sabinas, but the Sabinas hadrosaur is now considered a distinct taxon. More recently, the Cerro del Pueblo Formation kritosaur has been referred to Kritosaurus navajovius. We show it represents a new species related to Gryposaurus. The new species is distinguished by its large size, the shape of the premaxillary nasal process, the strongly downturned dentary, and massive denticles on the premaxilla’s palatal surface, supporting recognition of a new taxon, Coahuilasaurus lipani. The dinosaur assemblage of the Cerro del Pueblo Formation shows higher diversity than the contemporaneous fauna of the Horseshoe Canyon Formation in Alberta. Furthermore, Kritosaurini, Lambeosaurini, and Parasaurolophini all persist into the latest Campanian in southern Laramidia after disappearing from northern Laramidia. These patterns suggest declining herbivore diversity seen at high latitudes may be a local, rather than global phenomenon, perhaps driven by cooling at high latitudes in the Late Campanian and Maastrichtian.
Original language | English |
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Article number | 531 |
Journal | Diversity |
Volume | 16 |
Issue number | 9 |
Early online date | 1 Sept 2024 |
DOIs | |
Publication status | Published - 30 Sept 2024 |
Data Availability Statement
All data is available in the manuscript or the online Supplementary Material.Acknowledgements
Thanks to Jaime Urrutia-Fucugauchi for his gracious hospitality in Mexico City. We would like to thank the support and facilities granted during the review and preparation of material to V. Romero Mayen, J. Alvarado-Ortega, R. Hernández-Rivera, M. Montellano-Ballesteros, and G. Álvarez (IGM). Thanks to C. Díaz Frías for the life reconstruction of the new species. AARV thanks Consejo Nacional de Humanidades, Ciencia y Tecnología (CONAHCYT), and INAH for their support.Keywords
- Campanian
- Cretaceous
- Dinosauria
- Hadrosauridae
- Kritosaurini
- Laramidia
- Saurolophinae
- biogeography
ASJC Scopus subject areas
- Ecology
- Ecological Modelling
- Agricultural and Biological Sciences (miscellaneous)
- Nature and Landscape Conservation