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

Description

The sandstones of the formation were deposited in a fluvial environment. The formation has an estimated thickness of 460 metres (1,510ft) and overlies the Anita Formation, while it is overlain by the La Irene Formation. These formations are considered Campanian and Maastrichtian in age, respectively, 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.

Dinosaurs

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon MorphotaxonNotes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
TaxonReclassified taxonTaxon falsely reported as presentDubious taxon or junior synonymIchnotaxonOotaxonMorphotaxon

Ornithischians

Ornithischians of the Cerro Fortaleza Formation
TaxaSpeciesLocalityStratigraphic unitMaterialNotesImages
Ankylosauriaindet.Small-sized isolated osteoderms.Talenkauen santacrucensis
Iguanodontoideaindet.One incomplete maxillary tooth crown.
Ornithopodaindet.Two isolated caudal centra.
TalenkauenT. santacrucensisCorro Los Hornos near Lake Viedma.UpperA 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
TaxaSpeciesLocalityStratigraphic unitMaterialNotesImages
ClasmodosaurusC. spatulaLago ViedmaTwo incomplete teeth.A titanosaurDreadnoughtus Puertasaurus
Indeterminate32 isolated teeth.
DreadnoughtusD. schraniRio La Leona Valley,UpperFour incomplete proximal caudals and incomplete left astragalus.A titanosaur.
PuertasaurusP. reuiliCerros Los Hornos, La Leona.UpperA holotype based on four disarticulated vertebrae, specifically one cervical, one dorsal, and two caudal vertebrae.A titanosaur.

Theropods

Theropods of the Cerro Fortaleza Formation
TaxaSpeciesLocalityStratigraphic unitMaterialNotesImages
Abelisauridaeindet.An incomplete ziphodont tooth.Austrocheirus isasii Orkoraptor burkei
AustrocheirusA. isasiiHoyada Arroyo Seco.UpperAn incomplete right ulnaAn ceratosaurian theropod.
OrkoraptorO. burkeiCerro Los Hornos.UpperSeveral 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
TaxaSpeciesLocalityStratigraphic unitMaterialNotesImages
AtlantoceratodusA. iheringiCerro 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

Bibliography

  • Marenssi, Sergio A.; Casadio, Silvio; Santillana, Sergio N. (30 September 2003). [Stratigraphy and sedimentology of the Upper Cretaceous-Paleogene units outcropping on the southeastern margin of Lake Viedma, Santa Cruz Province, Argentina]. Revista de la Asociación Geológica Argentina (in Spanish). 58 (3): 403–416.
  • Varela, Augusto N.; Poiré, Daniel G.; Martin, Thomas; Gerdes, Axel; Goin, Francisco J.; Gelfo, Javier N.; Hoffmann, Simone (27 September 2012). (PDF). Andean Geology. 39 (3). doi:.