Limaysaurus includes a single type species, Limaysaurus tessonei, which was originally referred to the genus Rebbachisaurus as Rebbachisaurus tessonei, an African species, by Jorge Calvo and Leonardo Salgado in 1995.[1] However, a generic separation was proposed by Salgado, Alberto Garrido, Sergio Cocca and Juan Cocca, and the genus Limaysaurus was named in 2004. The generic name is derived from Río Limay which borders the region and from the specific name, tessonei, in honor of Lieto Tessone, who found the first and most complete holotype.[1] Their discovery shed some light on the distribution of Gondwanan dinosaurs in the mid-Cretaceous period. Several specimens of Limaysaurus are known, one of which (the holotype) is 80% complete, being one of the most complete Cretaceous sauropods ever found in South America.[2][3]
The holotype specimen, MUCPv-205, a partial skeleton including the back of the skull, was found in 1988 by Lieto Francisco Tessone, who is honoured in the specific name. It was afterwards collected, together with MUCPv-206, a second fragmentary skeleton, by José Bonaparte. These two adult specimens likely hailed from the top of the Candeleros Formation, which is dated to the early Cenomanian age. An additional smaller specimen, MUCPv-153, was found nearby, although it belonged to the base of the Huincul Formation, from the late Cenomanian.[1]
Skeletal reconstructions of the three known specimens
Limaysaurus was a medium-sized sauropod. Gregory S. Paul in 2010 estimated its length at fifteen meters (50 ft) and its weight at seven tonnes.[5] The neural spines on its back were very tall. The neural spines of the cervical and dorsal vertebrae are not V-shaped[6] but they have a simple and straight form like an I. Its teeth were curved, unlike those of Diplodocus which were pencil-shaped.[5] 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.[7] 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.
Classification
Restoration of Limaysaurus (front left) with contemporary dinosaurs
The describing authors in 2004 assigned Limaysaurus to the familyRebbachisauridae. The rebbachisaurids are a basalclade within the Diplodocimorpha, and their remains have been found in Cretaceous-age rocks in Europe, South America, and Africa. A cladistic analysis of macronarian sauropods (Salgado et al., 2004) demonstrated close affinities between Limaysaurus, the African genera Rebbachisaurus and Nigersaurus, and the South American genera Rayososaurus and Cathartesaura. [4][3]
^ abNovas, Fernando (2009). The Age of Dinosaurs in South America. USA: Indiana University Press. pp. 175–179.
^ abSalgado, L., Garrido, A., Cocca, S. E., and Cocca, J. R. (2004). "Lower Cretaceous rebbachisaurid sauropods from Cerro Aguada Del León, Neuquén Province, northwestern Patagonia, Argentina." Journal of Vertebrate Paleontology, 24(4): 903-912, December 2004.
^ abPaul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press, pp. 186 and 208.
^Holmes, Thom (2008). Time of the Giants. USA: Infobase Publishing. p. 48.
^Calvo, Jorge and Salgado, Leonardo (1996). A land bridge connection between South America and Africa during Albian-Cenomanian times based on sauropod dinosaur evidences. 39° Congresso Brasileiro de Geología , Anais (7): 392-393.
