Lago Colhué Huapí Formation

The Lago Colhué Huapí Formation is a Late Cretaceous geologic formation of the Chubut Group in the Golfo San Jorge Basin in Patagonia, Argentina. The formation, named after Lake Colhué Huapí, is overlain by the Salamanca Formation of the Río Chico Group and in some areas by the Laguna Palacios Formation.^[1]

Lago Colhué Huapí Formation
Stratigraphic range: Campanian-Maastrichtian ~80–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Chubut Group
Underlies	Laguna Palacios Formation and Río Chico Group (Salamanca Formation)
Overlies	Bajo Barreal Formation
Lithology
Primary	Tuff
Other	Sandstone
Location
Coordinates	45.6°S 68.5°W / -45.6; -68.5
Approximate paleocoordinates	48.2°S 55.2°W / -48.2; -55.2
Region	Central Patagonia
Country	Argentina
Extent	Golfo San Jorge Basin
Type section
Named for	Lake Colhué Huapí
Lago Colhué Huapí Formation (Argentina)

The strata of the Lago Colhué Huapé Formation were thought to pertain to the Bajo Barreal Formation, but are now recognized as a distinct stratigraphic unit in their own right.^[1][2]

Vertebrate paleofauna

Taxa recovered from the Lago Colhué Huapí Formation include the sauropods Aeolosaurus, and Argyrosaurus, as well as the hadrosaurid Secernosaurus and the probable elasmarian ornithopod Sektensaurus.^[3][4][5] The dubious possible ceratopsian Notoceratops was also present. The apex predator was an unnamed megaraptorid.^[1]

Dinosaurs

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Ornithischians

Ornithopods reported from the Lago Colhué Huapí Formation
Genus	Species	Locality	Stratigraphic position	Material	Notes	Images
Notoceratops	N. bonarelli		Upper.	An incomplete, toothless left dentary.	A dubious specimen that belongs to a ceratopsian family.
Secernosaurus	S. koerneri	Rio Chico	Upper	A partial skeleton.	A Saurolophinae hadrosaur.
Sektensaurus	S. sanjuanboscoi	Ephemeral island.	Upper	An associated partial skeleton.	An elasmarian ornithopod.

Sauropods

Sauropods reported from the Lago Colhué Huapí Formation
Genus	Species	Locality	Stratigraphic position	Material	Notes	Images
Aeolosaurus	A. colhuehuapensis	Ephemeral island.	Upper	A partial skeleton	A titanosaur.
Argyrosaurus	A. superbus	La Angostura, Río Chico.	Upper	A set of limb elements (left forelimb).	A titanosaur.
Elaltitan	E. lilloi	Río Senguerr bend	Lower	A partial skeleton.	A titanosaur.

Reptiles

Reptiles reported from the Lago Colhué Huapí Formation
Genus	Species	Locality	Stratigraphic position	Material	Notes	Images
Colhuehuapisuchus	C. lunai	Ephemeral island	Upper.	A mandible (Anterior portion of mandibles).	A peirosaurid notosuchian.

See also

• List of dinosaur-bearing rock formations
  • List of stratigraphic units with few dinosaur genera