Limaysaurus is an extinct genus represented by a single species of rebbachisaurid sauropod dinosaurs, which lived during the middle Cretaceous period, about 99.6 to 97 million years ago, in the Cenomanian, in what is now South America (specifically northwestern Patagonia).


Limaysaurus was a medium-sized sauropod. Gregory S. Paul in 2010 estimated its length at fifteen meters and its weight at seven tonnes. The neural spines on its back were very tall. The neural spines of the cervical and dorsal vertebrae are not V-shapes but they have a simple and straight form like an I. Its teeth were curved, unlike those of Diplodocus which were pencil-shaped. Another distinct characteristic of this sauropod is its phylogenetic relationship to Rebbachisaurus from Morocco.

This discovery supports the theory that there was a land bridge connecting South America to Africa 100 million years ago. It shared its habitat with Andesaurus and Giganotosaurus, characterized by plains with large and shallow lagoons. The climate was mild and humid. In fossil remains of Limaysaurus, gastroliths have been found, which were used to help the stomach to grind food.

The describing authors in 2004 assigned Limaysaurus to the family Rebbachisauridae. The rebbachisaurids are a basal clade within the Diplodocimorpha, and their remains have been found in Cretaceous-age rocks in Europe, South America, and Africa.