First occurrence of Daspletosaurus horneri (Tyrannosauridae, Tyrannosaurinae) in the Dinosaur Park Formation of Dinosaur Provincial Park, Alberta (Treaty 7 Territory)

A significant discovery of Daspletosaurus horneri in Dinosaur Provincial Park, Alberta, marks the first occurrence of this tyrannosaurine species outside its original range in Montana. Re-examination of specimen CMN 350, initially classified as D. torosus, revealed cranial features aligning with D. horneri, including a distinct lacrimal horn morphology and dentary bowing. This finding extends the known latitudinal range of the species by approximately 350 km and provides new insights into its intraspecific variability. The discovery also supports evidence of faunal turnover within the Dinosaur Park Formation, located 49 meters above the Oldman Formation contact.

Coppock, C. C., Powers, M. J., Voris, J. T., & Currie, P. J. (2025). First occurrence of Daspletosaurus horneri (Tyrannosauridae, Tyrannosaurinae) in the Dinosaur Park Formation of Dinosaur Provincial Park, Alberta (Treaty 7 Territory). Historical Biology, 38(6), 1970–1982. https://doi.org/10.1080/08912963.2025.2532735