two medium-sized herbivorous Pachycephalosaurus graze peacefully in a clearing surrounded by vegetation

and their discovery has given paleontologists a more complete view of ceratopsian diversity and evolution in North America

although its exact classification has been the subject of debate in the scientific community

a land mass in western North America during the Cretaceous Period

Psittacosaurus sibiricus es una especie extinta de dinosaurio ceratopsiano que vivió durante el período Cretácico temprano

Amargasaurus cazaui Dreadnoughtus two medium-sized herbivorous Pachycephalosaurus grazeAmargasaurus cazaui is a sauropod dinosaur that lived during the Early Cretaceous period, approximately 129 to 122 million years ago, in what is now South America, specifically in the region of Argentine Patagonia. Discovered in the La Amarga Formation, in the province of Neuqun, and first described in 1991, Amargasaurus is a member of the Dicraeosauridae family, a group of relatively small sauropods with distinctive morphological characteristics.