New hadrosaurid remains from the Late Cretaceous of Rio Negro Province (Argentina, Late Cretaceous)

Purpose Although the hadrosaurid record is more abundant in the Northern Hemisphere than in the Southern Hemisphere, it is in Argentina that most remains have been discovered, specifically in Patagonia. This record is characterized by an extensive geographical distribution of sites, some of them with abundant remains, many of which have been assigned to a high taxonomic level as indeterminate hadrosauroids or hadrosaurids. Despite the abundance of indeterminate remains, three hadrosaurid species are recorded between Rio Negro, La Pampa and Chubut provinces. Method Here, new cranial and postcranial remains from indeterminate hadrosauroids, hadrosaurids and euhadrosaurians deposited in several museums Rio Negro Province are presented and described here. Results and Conclusions These new remains increase the distribution and abundance of these dinosaurs in Argentina and highlight the need for an in-depth revision of the history and evolution of this ornithopod clade in South America.