Laramidia — Safekipedia Discoverer

Laramidia was an island continent that existed during the Late Cretaceous period (99.6–66 Ma), when the Western Interior Seaway split the continent of North America in two. In the Mesozoic era, Laramidia was an island land mass separated from Appalachia to the east by the Western Interior Seaway. It was home to many dinosaurs including ankylosaurs, ceratopsians, and tyrannosaurs. The seaway eventually shrank, split across the Dakotas, and retreated toward the Gulf of Mexico and the Hudson Bay. The masses joined, forming the continent of North America.

North America during the Campanian

Laramidia is named after the Laramide orogeny. The name was coined by J. David Archibald in 1996.

Geography

Laramidia stretched from modern-day Alaska to Mexico. This land was rich in dinosaur fossils and was home to many different kinds of dinosaurs. Some of these included tyrannosaurs, dromaeosaurids, troodontids, hadrosaurs, ceratopsians like Kosmoceratops and Utahceratops, pachycephalosaurs, and titanosaur sauropods. The climate varied greatly across Laramidia during the last 15 million years of the Cretaceous period, which helped create different groups of dinosaur species in various regions.

Range

Vertebrate fossils from many ancient animals have been found across a wide area, stretching from Alaska all the way to Coahuila. This shows that Laramidia was a large and important land area during its time.

Fauna

Dinosaurs found on the western coast

During the Late Cretaceous period, Laramidia was home to many different kinds of dinosaurs that evolved in unique ways because it was separated from the landmass to the east. The western United States has many fossils from this time, making it a great place for scientists to learn about these ancient animals.

One group of dinosaurs that lived on Laramidia were the tyrannosaurs, large meat-eating dinosaurs with big heads. Examples include Tyrannosaurus rex, Nanuqsaurus hoglundi, and Daspletosaurus. Another common type were the hadrosaurs, known as "duck-billed" dinosaurs, and Laramidia had many different kinds of them. Sauropods, the long-necked plant-eating dinosaurs, were also found on Laramidia but not as much in the land to the east.