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°06′S 44°42′W / 6.1°S 44.7°W |
| Approximate paleocoordinates | 2°24′S 12°06′W / 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
editThe following fossils were reported from the formation:[2]
See also
edit- Takutu Formation, contemporaneous formation of northern Brazil and Guyana
References
edit- ^ De Castro et al., 2016, p.532
- ^ Pastos Bons Formation at Fossilworks.org
- ^ Montefeltro, 2013, p.835
- ^ Gallo, V.; de Paiva, H. C. L.; Petra, R.; Brito, P. (2022). "Lophionotus parnaibensis, sp. nov. (Semionotiformes, Semionotidae) in the Upper Jurassic of the Parnaíba Basin, Northeastern Brazil". Journal of Vertebrate Paleontology. 41 (4). e1994983. doi:10.1080/02724634.2021.1994983. S2CID 246164511.
- ^ Yabumoto, 2007
Bibliography
edit- De Castro, David Lopes; Bezerra, Francisco Hilário; Fuck, Reinhardt Adolfo; Vidotti, Roberta Mary (2016), "Geophysical evidence of pre-sag rifting and post-rifting fault reactivation in the Parnaíba basin, Brazil", Solid Earth, 7 (2): 529–548, Bibcode:2016SolE....7..529L, doi:10.5194/se-7-529-2016, retrieved 2020-07-07
- Montefeltro, F.C.; Larsson, H. C. E.; França, M. A. G.; Langer, M. C. (2013), "A new neosuchian with Asian affinities from the Jurassic of northeastern Brazil", Naturwissenschaften, 100 (9): 835–841, Bibcode:2013NW....100..835M, doi:10.1007/s00114-013-1083-9, PMID 23893176, retrieved 2020-07-07
- Yabumoto, Y (2007), "A New Mesozoic coelacanth from Brazil (Sarcopterygii, Actinistia)", Paleontological Research, 12 (4): 329–343, doi:10.2517/prpsj.12.329