Cerro Fortaleza Formation

"Pari Aike Formation" redirects here and is not to be confused with Pali-Aike volcanic field.

The Cerro Fortaleza Formation, in older literature described as Pari Aike Formation, is a Late Cretaceous geologic formation of Campanian to Maastrichtian age^[1][2] (although it has formerly been reported to be Cenomanian to Santonian)^[3] of the Austral Basin in southern Patagonia, Argentina.

Cerro Fortaleza Formation
Stratigraphic range: Campanian to Maastrichtian ~76–70 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Underlies	La Irene Formation
Overlies	Anita Formation
Thickness	460 m (1,510 ft)
Lithology
Primary	Sandstone
Location
Coordinates	49.9°S 72.1°W / -49.9; -72.1
Approximate paleocoordinates	51.9°S 61.8°W / -51.9; -61.8
Region	Santa Cruz Province, southern Patagonia
Country	Argentina
Extent	Austral Basin
Cerro Fortaleza Formation (Argentina)

Description

The sandstones of the formation were deposited in a fluvial environment. The formation has an estimated thickness of 460 metres (1,510 ft) and overlies the Anita Formation, while it is overlain by the La Irene Formation.^[4] These formations are considered Campanian and Maastrichtian in age, respectively,^[4][3] making the Cerro Fortaleza Formation aged between them.

Paleobiota

The giant titanosaurs Puertasaurus and Dreadnoughtus, the megaraptoran Orkoraptor, the berthasaurid Austrocheirus isasii, and the ornithopod Talenkauen have been recovered from the formation alongside turtles and crocodiles.^[5][6][7]

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

Ornithischians of the Cerro Fortaleza Formation
Taxa	Species	Locality	Stratigraphic unit	Material	Notes	Images
Ankylosauria	indet.			Small-sized isolated osteoderms.
Iguanodontoidea	indet.			One incomplete maxillary tooth crown.
Ornithopoda	indet.			Two isolated caudal centra.
Talenkauen	T. santacrucensis	Corro Los Hornos near Lake Viedma.	Upper	A partial articulated skeleton with exception of the rear part of the skull, the tail, and the hands.	An elasmarian ornithopod.

Sauropods

Sauropods of the Cerro Fortaleza Formation
Taxa	Species	Locality	Stratigraphic unit	Material	Notes	Images
Clasmodosaurus	C. spatula	Lago Viedma		Two incomplete teeth.	A titanosaur	Dreadnoughtus Puertasaurus
	Indeterminate			32 isolated teeth.
Dreadnoughtus	D. schrani	Rio La Leona Valley,	Upper	Four incomplete proximal caudals and incomplete left astragalus.	A titanosaur.
Puertasaurus	P. reuili	Cerros Los Hornos, La Leona.	Upper	A holotype based on four disarticulated vertebrae, specifically one cervical, one dorsal, and two caudal vertebrae.	A titanosaur.

Theropods

Theropods of the Cerro Fortaleza Formation
Taxa	Species	Locality	Stratigraphic unit	Material	Notes	Images
Abelisauridae	indet.			An incomplete ziphodont tooth.		Austrocheirus isasii Orkoraptor burkei
Austrocheirus	A. isasii	Hoyada Arroyo Seco.	Upper	An incomplete right ulna	An ceratosaurian theropod.
Orkoraptor	O. burkei	Cerro Los Hornos.	Upper	Several isolated teeth, including two anteriormost, probably premaxillary teeth, left manual phalanx I-1, right, nearly complete fibula, and right ungual.	A megaraptoran

Fish

Fish of the Cerro Fortaleza Formation
Taxa	Species	Locality	Stratigraphic unit	Material	Notes	Images
Atlantoceratodus	A. iheringi	Cerro Los Hornos and Hoyada Arroyo Seco.		Four lower tooth plates, one lower tooth plate attached to a partial mandibular bone and four upper tooth plates.	A lungfish.

See also

• List of dinosaur-bearing rock formations