Pastos Bons Formation
Geologic formation in Brazil
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The Pastos Bons Formation is a Late Jurassic (Oxfordian to Kimmeridgian) geologic formation of the Parnaíba Basin in Maranhão, northeastern Brazil. The formation forms part of the sag phase of the basin. It overlies the Sardinha Formation and is overlain by the Mosquito Formation.[1] The fluvial to lacustrine sandstones and shales have provided fossils of a coelacanth fish, Parnaibaia maranhaoensis and a paralligatorid named after the formation, Batrachomimus pastosbonensis.
| Pastos Bons Formation | |
|---|---|
| Stratigraphic range: Oxfordian-Kimmeridgian ~ | |
Geologic map of the Parnaíba Basin with the Jurassic in red | |
| Type | Geological formation |
| Underlies | Mosquitos Formation |
| Overlies | Sardinha Formation |
| Lithology | |
| Primary | Sandstone |
| Other | Shale |
| Location | |
| Coordinates | 6.1°S 44.7°W |
| Approximate paleocoordinates | 2.4°S 12.1°W |
| Region | Maranhão |
| Country | Brazil |
| Extent | Parnaíba Basin |
| Type section | |
| Named for | Pastos Bons |
  Pastos Bons Formation (Brazil) | |
Fossil content
The following fossils were reported from the formation:[2]
Color key
|
Notes Uncertain or tentative taxa are in small text; |
Crocodylomorphs
| Crocodylomorphs of the Pasto Bons Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Batrachomimus[3] | B. pastosbonensis | A paralligatorid neosuchian. | ||||
Fish
| Fishes of the Pasto Bons Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Lophionotus[4] | L. parnaibensis | A semionotid fish. | ||||
| Parnaibaia[5] | P. maranhaoensis | A mawsoniid coelacanth. | ||||
| Quasimodichthys[6] | Q. piauhyensis | A semionotiform fish. | ||||
Plants
| Plants of the Pasto Bons Formation | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Araucariaceae Indet. | Indeterminate | |||||
See also
- Takutu Formation, contemporaneous formation of northern Brazil and Guyana