Location : Southwestern U.S.

A large member of the long-necked sauropod family, Alamosaurus was one of the last of these huge plant-eaters to live in what is now the United States. It is related to the titanosaurs, which were common in South America in the Cretaceous period.

It is an example of the re-introduction of the sauropods to North America from South America during the later part of the Cretaceous. It is the only known North American sauropod from the Late Cretaceous.