Laramidia

Laramidia was an island continent that existed a very long time ago during the Late Cretaceous period. At that time, the Western Interior Seaway split the continent of North America into two parts. In the Mesozoic era, Laramidia was an island separated from another land called Appalachia by the Western Interior Seaway. Many dinosaurs lived there, including ankylosaurs, ceratopsians, and tyrannosaurs. Over time, the seaway became smaller. It moved across the Dakotas and headed toward the Gulf of Mexico and the Hudson Bay. Eventually, the land masses joined together to form the continent of North America.

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

Geography

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

Range

Many fossils from ancient animals have been found from Alaska to Coahuila. This shows that Laramidia was a large and important place long ago.

Fauna

During the Late Cretaceous period, Laramidia was home to many different kinds of dinosaurs. These dinosaurs evolved in unique ways because Laramidia was separated from the land 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. These were 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. 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.