Río Belgrano FormationThe Río Belgrano Formation is a Barremian to Aptian geologic formation of the Austral Basin in Patagonia, southern Argentina. Among others, pterosaur and ichthyosaur fossils have been recovered from the formation.Fossil contentThe following fossils have been recovered from the formation:Hatchericeras patagonensePalaeastacus terraereginaePlatypterygius hauthaliSanmartinoceras africanumTonohamites aequicingulatus ?Anhangueridae indet.