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.

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. The upper part of the Lago Colhué Huapí Formation has been dated to the upper Maastrichtian age of the late Cretaceous period. A basalt flow in the formation has been dated to ± 0.55 million years ago, reinforcing the Late Maastrichtian age.

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. The dubious ornithischian Notoceratops was also present.

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

Ornithopods from the Lago Colhué Huapí Formation
GenusSpeciesLocalityStratigraphic positionMaterialNotesImages
NotoceratopsN. bonarelliiUpperAn incomplete, toothless left dentaryA dubious genasaurian ornithischianSecernosaurus
SecernosaurusS. koerneriRio ChicoUpperA partial skeletonA saurolophine hadrosaur
SektensaurusS. sanjuanboscoiAn ephemeral islandUpperAn associated partial skeletonAn elasmarian ornithopod

Sauropods

Sauropods from the Lago Colhué Huapí Formation
GenusSpeciesLocalityStratigraphic positionMaterialNotesImages
AeolosaurusA. colhuehuapensisAn ephemeral islandUpperA partial skeletonA titanosaurAeolosaurus Argyrosaurus
ArgyrosaurusA. superbusLa Angostura, Río Chico.UpperA set of limb elements (left forelimb)A titanosaur
ElaltitanE. lilloiRío Senguerr bendLowerA partial skeletonA titanosaur
Lithostrotia indet.IndeterminateMiddleA partial skeletonA titanosaur

Theropods

Theropods from the Lago Colhué Huapí Formation
GenusSpeciesLocalityStratigraphic positionMaterialNotesImages
JoaquinraptorJ. casaliValle JoaquínUpperA partial skeleton including skull bones, vertebrae, the pectoral girdle, and forelimb and hindlimb bonesA megaraptorid theropodJoaquinraptor
Theropoda indet.IndeterminateAn ephemeral island, Mocha PeninsulaUpperA manual ungual (hand claw) and possible metatarsal IIIA possible megaraptoran theropod

Other reptiles

Reptiles from the Lago Colhué Huapí Formation
GenusSpeciesLocalityStratigraphic positionMaterialNotesImages
ColhuehuapisuchusC. lunaiAn ephemeral islandUpper.A mandible (Anterior portion of mandibles)A peirosaurid notosuchian

Fish

Fishes from the Lago Colhué Huapí Formation
GenusSpeciesLocalityStratigraphic positionMaterialNotesImages
MetaceratodusM. kaopenUpperA ceratodontid lungfish

See also

Bibliography

  • Casal, Gabriel A.; Allard, José O.; Foix, Nicolás (March 2015). [Stratigraphic and paleontological analysis of the Upper Cretaceous in the San Jorge Gulf Basin: a new lithostratigraphic unit for the Chubut Group]. Revista de la Asociación Geológica Argentina (in Spanish). 72 (1): 77–95. hdl:.
  • Casal, Gabriel (30 April 2007). [Aeolosaurus colhuehuapensis sp. nov.(Sauropoda, Titanosauria) from the Lower Barreal Formation, upper Cretaceous of Argentina]. Revista Brasileira de Paleontologia (in Spanish). 10 (1): 53–62. Bibcode:. doi:.
  • Clyde, W.C.; Wilf, P.; Slingerland, Iglesias A.; Barnum, T.; Bijl, P.K. (2014), "New age constraints for the Salamanca Formation and lower Río Chico Group in the western San Jorge Basin, Patagonia, Argentina: implications for Cretaceous—Paleogene extinction recovery and land mammal age correlations", Geological Society of America Bulletin, 126 (3–4): 289–306, Bibcode:, doi:, hdl:
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  • Mannion, P.D.; Otero, A. (2012), "A reappraisal of the Late Cretaceous Argentinean sauropod dinosaur Argyrosaurus superbus, with a description of a new titanosaur genus", Journal of Vertebrate Paleontology, 32 (3): 614–638, Bibcode:, doi:, hdl:
  • Martínez, R.D.F.; Lamanna, M.C.; Novas, F.E.; Ridgely, R.C.; Casal, G.A.; Martínez, J.E. (2016), "A Basal Lithostrotian Titanosaur (Dinosauria: Sauropoda) with a Complete Skull: Implications for the Evolution and Paleobiology of Titanosauria", PLoS ONE, 11 (4) e0151661, Bibcode:, doi:, PMC , PMID
  • Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), (2nd ed.), Berkeley: University of California Press, pp. 1–880, ISBN 0-520-24209-2{{citation}}: CS1 maint: publisher location (link)
  • Vallati, Patricia; De Sosa Tomas, Andrea; Casal, Gabriel (January 2020). "A Maastrichtian terrestrial palaeoenvironment close to the K/Pg boundary in the Golfo San Jorge basin, Patagonia, Argentina". Journal of South American Earth Sciences. 97 102401. Bibcode:. doi:.