Alamosaurus

sauropod · dinosaur · Late Cretaceous · North America

Titanosaurus size. Alamosaurus was one of the biggest land animals ever to walk Earth, belonging to the titanosaur family of sauropods. These dinosaurs had extremely long necks, long tails, and four powerful legs that supported their massive bodies.

Long-lost return. For about 30 million years, sauropods had completely disappeared from North America's fossil record. Alamosaurus suddenly shows up again at the very end of the Cretaceous period, suggesting it either migrated from South America or Asia or was related to dinosaurs from those continents.

Southwestern home. Alamosaurus lived in what is now the southwestern United States during the Maastrichtian age, the final period of the dinosaur era. Fossils of this dinosaur have been found in places like New Mexico and Texas.

One special species. Scientists have identified only one species of Alamosaurus, called Alamosaurus sanjuanensis. This single-species genus tells us that this particular long-necked dinosaur was unique and distinct from all other sauropods of its time.