Pachyrhinosaurus lakustai was a species of ceratopsid dinosaur that lived during the Late Cretaceous period, around 73.5 million years ago. This dinosaur, which measured up to 6 meters (20 feet) in length and weighed approximately 4 metric tons, was distinguished by its thickened nasal boss, a unique feature among ceratopsians. Pachyrhinosaurus lakustai also had a large frill adorned with various bony ornamentations, adding to its distinctive appearance. It was a herbivore, using its beak-like mouth to feed on tough vegetation. Fossils of Pachyrhinosaurus lakustai have been discovered in the Wapiti Formation of Alberta, Canada, providing significant insights into the diversity and evolution of horned dinosaurs.