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 , 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
Ornithischians
Ornithopods from the Lago Colhué Huapí Formation Genus Species Locality Stratigraphic position Material Notes ImagesNotoceratops N. bonarellii Upper An incomplete, toothless left dentary A dubious genasaurian ornithischian Secernosaurus S. koerneri Rio Chico Upper A partial skeleton A saurolophine hadrosaurSektensaurus S. sanjuanboscoi An ephemeral island Upper An associated partial skeleton An elasmarian ornithopod
Sauropods
Sauropods from the Lago Colhué Huapí Formation Genus Species Locality Stratigraphic position Material Notes ImagesAeolosaurus A. colhuehuapensis An ephemeral island Upper A partial skeleton A titanosaur Argyrosaurus A. superbus La Angostura, Río Chico. Upper A set of limb elements (left forelimb) A titanosaurElaltitan E. lilloi Río Senguerr bend Lower A partial skeleton A titanosaurLithostrotia indet.Indeterminate Middle A partial skeleton A titanosaur
Theropods
Theropods from the Lago Colhué Huapí Formation Genus Species Locality Stratigraphic position Material Notes ImagesJoaquinraptorJ. casali Valle Joaquín Upper A partial skeleton including skull bones, vertebrae, the pectoral girdle, and forelimb and hindlimb bones A megaraptorid theropodTheropoda indet.Indeterminate An ephemeral island, Mocha Peninsula Upper A manual ungual (hand claw) and possible metatarsal III A possible megaraptoran theropod
Other reptiles Reptiles from the Lago Colhué Huapí Formation Genus Species Locality Stratigraphic position Material Notes ImagesColhuehuapisuchus C. lunai An ephemeral island Upper. A mandible (Anterior portion of mandibles) A peirosaurid notosuchian
Fish Fishes from the Lago Colhué Huapí Formation Genus Species Locality Stratigraphic position Material Notes ImagesMetaceratodusM. kaopen Upper A ceratodontid lungfish
Plants Plants of the Lago Colhué Huapí Formation Genus Species Location Stratigraphic position Material Notes Images Azolla A. colhuehuapensis An aquatic fern Spinizonocolpites S. riochiquensis A palm tree
See also List of dinosaur-bearing rock formations List of stratigraphic units with few dinosaur genera
References
Bibliography