A juvenile chasmosaurine ceratopsid (Dinosauria, Ornithischia) from the Dinosaur Park Formation, Alberta, Canada

A juvenile Chasmosaurus, representing one of the smallest specimens of its kind, was discovered in Dinosaur Provincial Park, Alberta. This 1.5-meter-long skeleton, missing only the front limbs and tail tip, provides critical insights into the growth and development of ceratopsid dinosaurs. Notably, the specimen exhibits unique cranial features such as a narrow frill without a posterior embayment, co-ossified bones despite its small size, and an incipient horncore on the nasals. Phylogenetic analysis suggests that when age-dependent characters are excluded, this juvenile clusters with other Chasmosaurus species, indicating that such traits should be treated cautiously in evolutionary studies to avoid misclassification.

Currie, P. J., Holmes, R. B., Ryan, M. J., & Coy, C. (2016). A juvenile chasmosaurine ceratopsid (Dinosauria, Ornithischia) from the Dinosaur Park Formation, Alberta, Canada. Journal of Vertebrate Paleontology, 36(2). https://doi.org/10.1080/02724634.2015.1048348