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

It is believed that this crest had several functions

a land mass in western North America during the Cretaceous Period

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

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

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.