The Dorotea Formation is a geological formation in the Río de Las Chinas Valley of the Magallanes Basin in Patagonian Chile whose strata date back to the Campanian to Maastrichtian of the Late Cretaceous.Dorotea Formation at Fossilworks.org
Description The Dorotea Formation was first described by Katz in 1963. The formation comprises sandstones with frequent conglomerate lenses, concretionary levels and claystones. The Dorotea Formation includes calcareous sandstones with abundant marine invertebrate and fragmentary vertebrate fossils. Hervé et al. (2004) obtained a maximum radiometric age of 67.4 ± 1.5 Ma from detrital zircons contained in sandstones of the Dorotea Formation. Near the top of the formation is an iridium anomaly, correlated with the Cretaceous–Paleogene boundary; this is the southernmost K–Pg boundary site known from South America.
The mudstones and sandstones of the formation were deposited in a fluvial environment. The formation conformably overlies the Tres Pasos Formation and is unconformably overlain by the Lutetian to Bartonian Man Aike Formation.Goin et al., 2020, p.9 The thickness of the formation ranges from in the Sierra Baguales in the north to in the eponymous Sierra Dorotea in the south.Otero et al., 2015, p.240
Fossil content The following fossils were reported from the formation:Río de las Chinas Valley at Fossilworks.org
Amphibians +Amphibians of Dorotea FormationTaxaSpeciesMaterialNotesImages Anura Indeterminate A frog
Reptiles +Reptiles of Dorotea FormationTaxaSpeciesLocalityMaterialNotesImagesAristonectinaeOtero et al., 2015 IndeterminateAristonectes A. sp. Yaminuechelyscf. Yaminuechelys sp.Alarcón Muñoz et al., 2020 Panchelidae Indeterminate Saurópodo sector (Section SP-17). Distal fragment of right humerus and distal end of right femur.ElasmosauridaeIndeterminate
Dinosaurs Ornithischians +Ornithischians of Dorotea FormationTaxaSpeciesLocalityMaterialNotesImagesGonkoken G. nanoiLoma Koken Several incomplete specimens belonging to individuals of different ages A hadrosauroid OrnithischiaIndeterminateStegourosS. elengassen CPAP-3165 (holotype), a holotype consists of a relatively complete skeleton with a skull and lower jaws. A parankylosaur
Saurischians +Saurischians of Dorotea FormationTaxaSpeciesMaterialNotesImages Enantiornithes Indeterminate Megaraptoridae Indeterminate Ornithurae Indeterminate Sauropoda Indeterminate UnenlagiinaeIndeterminate Theropoda Indeterminate
Mammals +Mammals of Dorotea FormationTaxaSpeciesLocalityMaterialNotesImagesMagallanodonGoin et al., 2020M. baikashkenkeGoin et al., 2020 Mammal quarry from the Río de Las Chinas valley A first lower left molariform A gondwanathere OrretheriumO. tzen Mammal quarry from the Río de Las Chinas valley A fragmented lower jaw.A mesungulatid mammalMammalia IndeterminateYeutheriumY. pressor'Black Bone' LocalityA left maxilla fragment with M1, roots of M2 and mesial roots of M3.A subantarctic reigitheriidae mammal
Fish +Fish of Dorotea FormationTaxaSpeciesMaterialNotesImages IschyrhizaI. chilensisCarcharias C. sp. Serratolamna Indeterminate
Invertebrates +Invertebrates of Dorotea FormationTaxaSpeciesLocalityMaterialNotesImages Dorotheus Dorotheus guidensisKuschel, 1959 Pterotrigonia P. cazadorianaOtero et al., 2009GunnaritesG. sp.PachydiscusP. aff. gollevilensis
See also List of dinosaur-bearing rock formations Quiriquina Formation Chorrillo Formation Allen Formation, Campanian to Maastrichtian fossiliferous formation of the Neuquén Basin Angostura Colorada Formation, Campanian to Maastrichtian fossiliferous formation of the North Patagonian Massif La Colonia Formation, Campanian to Maastrichtian formation of the Cañadón Asfalto Basin Colorado Formation, Campanian to Maastrichtian fossiliferous formation of the Colorado Basin Lago Colhué Huapí Formation, Campanian to Maastrichtian fossiliferous formation of the Golfo San Jorge Basin López de Bertodano Formation Snow Hill Island Formation Sobral Formation
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