Itapecuru Formation

The Itapecuru Formation is a geological formation in Itapecuru Mirim, Maranhão, Brazil.

OverliesCodó, Grajaú and Piauí Formations

Thicknessup to 2,000 m (6,600 ft) in São Luís Basin
700 m (2,300 ft) in Parnaíba Basin

Quick facts Type, Underlies ...

Itapecuru Formation
Stratigraphic range: Aptian-Cenomanian ~120–95 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Underlies	Alluvium and Corda Formation
Overlies	Codó, Grajaú and Piauí Formations
Thickness	up to 2,000 m (6,600 ft) in São Luís Basin 700 m (2,300 ft) in Parnaíba Basin
Lithology
Primary	Mudstone, sandstone
Other	Breccia, diamictite
Location
Coordinates	3°23′30″S 44°21′30″W
Approximate paleocoordinates	8.6°S 15.9°W / -8.6; -15.9
Region	Itapecuru Mirim Maranhão
Country	Brazil
Extent	São Luís and Parnaíba Basins
Type section
Named for	Itapecuru Mirim
Itapecuru Formation (Brazil)

It was formed during the Aptian to Albian stages of the Early Cretaceous.^[1] Dinosaur remains are among the fossils that have been recovered from the formation.^[2]

Fossil content

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.

Dinosaurs

Sauropods

More information Sauropods of the Itapecuru Formation, Genus ...

Sauropods of the Itapecuru Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Amazonsaurus^[3]	A. maranhensis				A rebbachisaurid sauropod	Amazonsaurus Dasosaurus
Dasosaurus^[4]	D. tocantinensis		Lower	A partial skeleton	A somphospondyli sauropod
Sauropoda indet.^[2]	Indeterminate

Theropods

More information Theropods of the Itapecuru Formation, Genus ...

Theropods of the Itapecuru Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Abelisauridae Indet.^[2]	Indeterminate
Carcharodontosauridae Indet.^[5]	Indeterminate			Tooth
Oxalaia^[2]	O. quilombensis				A spinosaurid theropod
Theropoda indet.^[2]	Indeterminate

Crocodylomorphs

More information Crocodylomorphs of the Itapecuru Formation, Genus ...

Crocodylomorphs of the Itapecuru Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Candidodon^[6]	C. itapecuruense				A candidodontid notosuchian

Turtles

More information Turtles of the Itapecuru Formation, Genus ...

Turtles of the Itapecuru Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Araripemys	A. barretoi				A araripemydid side-necked turtle
Itapecuruemys^[7]	I. amazoniensis				A bothremydid side-necked turtle

Fish

More information Fishes of the Itapecuru Formation, Genus ...

Fishes of the Itapecuru Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Arganodus	A. tiguidiensis				A arganodontid lungfish
Ceratodus	C. africanus				A ceradodontid lungfish
Mawsonia	M. gigas				A mawsoniid coelacanth

References

[1]
Ferreira, Neila N.; Ferreira, Elizabete P.; Ramos, Renato R.C.; Carvalho, Ismar S. (2016). "Palynological and sedimentary analysis of the Igarapé Ipiranga and Querru 1 outcrops of the Itapecuru Formation (Lower Cretaceous, Parnaíba Basin), Brazil". Journal of South American Earth Sciences. 66: 15–31. Bibcode:2016JSAES..66...15F. doi:10.1016/j.jsames.2015.12.005. ISSN 0895-9811.
[2]
Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 600-604. ISBN 0-520-24209-2.
[3]
de Souza Carvalho, Ismar; dos Santos Avilla, Leonardo; Salgado, Leonardo (2003). "Amazonsaurus maranhensis gen. et sp. nov. (Sauropoda, Diplodocoidea) from the Lower Cretaceous (Aptian–Albian) of Brazil". Cretaceous Research. 24 (6). Elsevier BV: 697–713. Bibcode:2003CrRes..24..697D. doi:10.1016/j.cretres.2003.07.005. ISSN 0195-6671.
[4]
Mayer, E. L.; Silva Junior, J. C. G.; Kerber, L.; Navarro, B. A.; Bandeira, K. L. N.; Cisneros, J. C.; Sousa, E. P.; Pereira, A. A.; Medeiros, M. A.; Lindoso, R. M.; Cavalcanti Neto, F. P.; Ghilardi, A. M.; Aureliano, T.; Godoy, P. L.; Ferreira, G. S.; Langer, M. C. (2026). "A new titanosauriform with European affinities in the Early Cretaceous of Brazil: insights on Somphospondyli phylogeny, histology and biogeography". Journal of Systematic Palaeontology. 24 2601579. doi:10.1080/14772019.2025.2601579.
[5]
França, T. C.; Brilhante, N. S.; Delcourt, R.; Silva, J. L.; Hendrickx, C.; Medeiros, M. A.; Costa, F. R. (2025). "A carcharodontosaurid tooth from "Boca de Forno" Ravine of the Itapecuru Formation, Parnaíba Basin, Maranhão, Brazil". Cretaceous Research. 106163. doi:10.1016/j.cretres.2025.106163.
[6]
Candidodon itapecuruense type locality at Fossilworks.org
[7]
Batista, Diego L.; de Sousa Carvalho, I.; de la Fuente, M.S. (2020). "A new Cretaceous (Pleurodira: Pelomedusoides) from the Lower Cretaceous of Parnaíba Basin, Brazil": Journal of South American Earth Sciences. https://doi.org/10.1016/j.jsames.2020.102872