Pastos Bons Formation

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 ~161–151 Ma PreꞒ Ꞓ O S D C P T J K Pg N
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 / -6.1; -44.7
Approximate paleocoordinates	2.4°S 12.1°W / -2.4; -12.1
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 Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

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