Río Belgrano Formation
Stratigraphic range: Barremian-Aptian
Type	Geological formation
Unit of	Pueyrredón Group
Underlies	Río Tarde Formation
Overlies	Río Mayer Formation
Lithology
Primary	Sandstone
Location
Coordinates	48°00′S 72°00′W / 48.0°S 72.0°W / -48.0; -72.0
Approximate paleocoordinates	48°00′S 35°30′W / 48.0°S 35.5°W / -48.0; -35.5
Region	Santa Cruz Province
Country	Argentina
Extent	Austral Basin
Río Belgrano Formation (Argentina)

The 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.^[1]

The following fossils have been recovered from the formation:^[2]

• Hatchericeras patagonense
• Palaeastacus terraereginae
• Platypterygius hauthali^[3]
• Sanmartinoceras africanum
• Tonohamites aequicingulatus
• ?Anhangueridae indet.

• List of pterosaur-bearing stratigraphic units

• Páramo Fonseca, María Eurídice (2018), "Restos apendiculares de un ictiosaurio oftalmosáurido del Barremiano inferior de Villa de Leiva, Colombia", Boletín de Geología, 40: 15–30, doi:10.18273/revbol.v40n1-2018001, retrieved 2019-02-06

• M. B. Aguirre Urreta. 1989. The Cretaceous decapod Crustacea of Argentina and the Antarctic Peninsula. Palaeontology 32(3):499-552
• M. B. Aguirre Urreta. 1986. Aptian ammonites from the Argentinian Austral Basin. The Subfamily Helicancylinae Hyatt, 1894. Annals of the South African Museum 96(7):271-314
• J. F. Bonaparte. 1978. El Mesozoico de America de Sur y sus Tetrapodos [The Mesozoic of South America and its tetrapods]. Opera Lilloana 26:1-596