Massive Dome-Headed Dinosaur Discovered in Montana Fossil Trove

In a significant paleontological discovery, researchers have unearthed a new species of dome-headed dinosaur in Montana. The dinosaur, named Brontotholus harmoni, belongs to the pachycephalosaurid family and is believed to have lived around 75 million years ago during the Late Cretaceous period.

Five specimens of B. harmoni were uncovered in the Two Medicine Formation in Glacier County, Montana. This marks the first time a pachycephalosaurid from the Late Cretaceous has been found in the region. Pachycephalosaurids are known for their distinctive, thickened skull domes and were bipedal herbivores.

The discovery of B. harmoni provides valuable insights into the morphology and diversity of pachycephalosaurids. At an estimated 10 feet in length, this dinosaur is the third-largest of its kind to be found in North America, indicating that the clade contained relatively large-bodied species as early as the Middle Campanian stage of the Late Cretaceous.

The researchers note that during the late Cretaceous, western North America experienced fluctuating sea levels, which allowed for the evolution of various dinosaur groups, including tyrannosaurids, ceratopsids, hadrosaurids, and pachycephalosaurids. The new fossil find adds to our understanding of how these dome-headed dinosaurs adapted and thrived in their ancient environments.