The Açu Formation is an Early Cretaceous (Albian) geologic formation of the Potiguar Basin in Ceará, northeastern Brazil. The formation comprises coarse-grained sandstones deposited in a fluvio-deltaic environment. The Açu Formation, belonging to the Apodi Group, has provided fossils of an indeterminate rebbachisaurid.
Description
The Açu Formation was deposited in a passive margin setting, overlying the Alagamar Formation and is overlain by the Jandaíra Formation. In the petroleum producing Potiguar Basin, the formation is a reservoir rock.[1]
Fossil content
The following fossils were reported from the formation:[2]
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Color key
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Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
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Dinosaurs
Sauropods
Theropods
Crocodylomorphs
Fish
Crustaceans
| Crustaceans of the Açu Formation
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| Genus
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Species
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Location
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Stratigraphic position
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Material
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Notes
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Images
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| Unusuropode
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U. castroi
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Ceará
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Albian
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A isopod
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Molluscs
Bivalves
Gastropods
Echinoderms
Plants
Bibliography
- Gomes da Costa Pereira, Paulo Victor; Ribeiro, Theo Baptista; Brusatte, Stephen Louis; Dos Anjos Candeiro, Carlos Roberto; da Silva Marinho, Thiago; Paglarelli Bergqvist, Lilian (2020), "Theropod (Dinosauria) diversity from the Potiguar basin (Early-late Cretaceous Albian – Cenomanian), Northeast Brazil" (PDF), Cretaceous Research, in press 104517, doi:10.1016/j.cretres.2020.104517, hdl:20.500.11820/849a673d-9aa1-4b8e-be0c-f630af8a5d5e
- Maraschin, Anderson; Mizusaki, Ana Maria P.; Vasconcelos, P.M.; Hinrichs, Ruth (2010), "Depositional age definition of the Açu Formation (Potiguar Basin, northeastern Brazil) through 40Ar-39Ar dating of early-authigenic K-feldspar overgrowths", Pesquisas Em Geociencias, 37: 85–96, doi:10.22456/1807-9806.22649, retrieved 2020-06-18
References
- ^ Maraschin et al., 2010, p.87
- ^ Açu Formation at Fossilworks.org
- ^ Paulo Victor Luiz Gomes da Costa Pereira; Ingrid Martins Machado Garcia Veiga; Theo Baptista Ribeiro; Ryan Henrique Bezerra Cardozo; Carlos Roberto dos Anjos Candeiro; Lilian Paglarelli Bergqvist (2020). "The path of giants: a new occurrence of Rebbachisauridae (Dinosauria, Diplodocoidea) in the Açu Formation, NE Brazil, and its paleobiogeographic implications". Journal of South American Earth Sciences. 100 102515. Bibcode:2020JSAES.10002515P. doi:10.1016/j.jsames.2020.102515. S2CID 212916577.
- ^ Pereira, P. V. L. G. C.; Bandeira, K. L. N.; Vidal, L. S.; Ribeiro, T. B.; Candeiro, C. R. A.; Bergqvist, L. P. (2024). "A new sauropod species from north-western Brazil: biomechanics and the radiation of Titanosauria (Sauropoda: Somphospondyli)". Zoological Journal of the Linnean Society. 202 (4). doi:10.1093/zoolinnean/zlae054.
- ^ Pereira, P.V.L.G.C.; Marinho, T.S.; Candeiro, C.R.A.; Bergqvist, L.P. (2018). "A new titanosaurian (Sauropoda, Dinosauria) osteoderm from the Cretaceous of Brazil and its significance". Ameghiniana. 55 (6): 644–650. doi:10.5710/AMGH.26.08.2018.3168.
- ^ Ribeiro, T. B.; Vecchietti, L. F.; Candeiro, C. R. A.; Canale, J. I.; Bergqvist, L. P.; Brito, P. M.; Pereira, P. V. L. G. C. (2025). "Overabundance of abelisaurid teeth in the Açu Formation (Albian-Cenomanian), Potiguar Basin, Northeastern Brazil: morphometric, cladistic and machine learning approaches". Journal of Vertebrate Paleontology. e2487366. doi:10.1080/02724634.2025.2487366.
- ^ Brito, P. M.; Veiga, I. M.; Dutheil, D. B.; Bergqvist, L. P. (2025). "First occurrence of Distobatus Werner, 1989 (Elasmobranchii: Hybodontiformes) in the middle Cretaceous (Albian–Cenomanian) of Brazil: Taxonomic and biogeographical implications". Cretaceous Research. 171 106119. 106119. doi:10.1016/j.cretres.2025.106119.
- ^ Costa, V. P. G.; Aureliano, T.; Santos, C. L. A.; Ghilardi, A. M. (2025). "The oldest occurrence of Lepisosteus (Ginglymodi: Lepisosteiformes: Lepisosteidae) in Gondwana". Historical Biology: An International Journal of Paleobiology: 1–8. doi:10.1080/08912963.2025.2504475.