Paleontologists have unearthed the fossilized remains of two new small-bodied pachycephalosaurines: one in the Dinosaur Park Formation of Alberta and the other in the Hell Creek Formation of Montana. Sphaerotholus buchholtzae (smaller species) fighting below larger pachycephalosaurs, the Hell Creek Formation, Montana, the United States. Image credit: ABelov2014 / CC BY-SA 3.0 Deed. One of the new dinosaur species, named Sphaerotholus lyonsi, lived...
