Itapecuru Formation Explained

Itapecuru Formation
Type:	Geological formation
Period:	Cenomanian
Age:	Aptian-Cenomanian ~
Prilithology:	Mudstone, sandstone
Otherlithology:	Breccia, diamictite
Namedfor:	Itapecuru Mirim
Region:	Itapecuru Mirim Maranhão
Country:	Brazil
Coordinates:	-3.3917°N -44.3583°W
Paleocoordinates:	-8.6°N -15.9°W
Underlies:	Alluvium and Corda Formation
Overlies:	Codó, Grajaú and Piauí Formations
Thickness:	up to 2000m (7,000feet) in São Luís Basin 700m (2,300feet) in Parnaíba Basin
Extent:	São Luís and Parnaíba Basins

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

Dinosaurs

Sauropods

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

Theropods

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

Turtles

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

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

Notes and References

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. 10.1016/j.jsames.2015.12.005. 0895-9811. 2016JSAES..66...15F.
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. .
de Souza Carvalho . Ismar . dos Santos Avilla . Leonardo . Salgado . Leonardo . Amazonsaurus maranhensis gen. et sp. nov. (Sauropoda, Diplodocoidea) from the Lower Cretaceous (Aptian–Albian) of Brazil . Cretaceous Research . Elsevier BV . 24 . 6 . 2003 . 0195-6671 . 10.1016/j.cretres.2003.07.005 . 697–713. 2003CrRes..24..697D .
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. . 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 . 10.1080/14772019.2025.2601579 . 2601579 . Langer . M. C.. subscription .
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 . 10.1016/j.cretres.2025.106163 .
https://paleobiodb.org/classic/displayCollResults?collection_no=118187 Candidodon itapecuruense type locality
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