| Dorotea Formation | |
| Type: | Geological formation |
| Period: | Maastrichtian |
| Age: | Late Campanian-Maastrichtian ~ |
| Prilithology: | Sandstone, claystone |
| Otherlithology: | Conglomerate |
| Namedfor: | Sierra Dorotea |
| Namedby: | Katz |
| Year Ts: | 1963 |
| Region: | Magallanes Region |
| Coordinates: | -50.7°N -72.5°W |
| Paleocoordinates: | -52.9°N -60.5°W |
| Underlies: | Man Aike Formation |
| Overlies: | Tres Pasos Formation |
| Thickness: | 100- |
| Extent: | Río de Las Chinas Valley, Magallanes Basin |
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.[1]
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.
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.[2] The thickness of the formation ranges from 100m (300feet) in the Sierra Baguales in the north to 350m (1,150feet) in the eponymous Sierra Dorotea in the south.[3]
The following fossils were reported from the formation:[4]
| Taxa | Species | Material | Notes | Images | |
|---|---|---|---|---|---|
| Aristonectinae[5] | Indeterminate | ||||
| Aristonectes | Aristonectes sp. | ||||
| Yaminuechelys | cf. Yaminuechelys sp.[6] | ||||
| Panchelidae | Indeterminate | ||||
| Elasmosauridae | Indeterminate |
| Taxa | Species | Material | Notes | Images | |
|---|---|---|---|---|---|
| Enantiornithes[7] | Indeterminate | ||||
| Gonkoken[8] | G. nanoi | Several incomplete specimens belonging to individuals of different ages | A hadrosauroid | ||
| Megaraptoridae | Indeterminate | ||||
| Ornithischia | Indeterminate | ||||
| Ornithurae | Indeterminate | ||||
| Sauropoda | Indeterminate | ||||
| Stegouros | S. elengassen | CPAP-3165 (holotype), a holotype consists of a relatively complete skeleton with a skull and lower jaws. | A parankylosaur | ||
| Unenlagiinae | Indeterminate | ||||
| Theropoda | Indeterminate |
| Taxa | Species | Material | Notes | Images | |
|---|---|---|---|---|---|
| Magallanodon[9] | M. baikashkenke[10] | A gondwanathere | |||
| Orretherium | O. tzen[11] | A mesungulatid mammal | |||
| Mammalia | Indeterminate |
| Taxa | Species | Material | Notes | Images | |
|---|---|---|---|---|---|
| Ischyrhiza | I. chilensis | ||||
| Carcharias | C. sp. | ||||
| Serratolamna | Indeterminate |
| Taxa | Species | Material | Notes | Images | |
|---|---|---|---|---|---|
| Dorotheus | Dorotheus guidensis[12] | ||||
| Pterotrigonia | P. cazadoriana[13] | ||||
| Gunnarites | G. sp. | ||||
| Pachydiscus | P. aff. gollevilensis |