Alcântara Formation
Stratigraphic range: Cenomanian
TypeGeological formation
Unit ofItapecuru Group
UnderliesCujupe Formation
OverliesUndifferentiated unit
Thickness30–35 m (98–115 ft)
Lithology
PrimarySandstone
OtherClaystone, conglomerate
Location
Coordinates2°30′S 44°30′W / 2.5°S 44.5°W / -2.5; -44.5Coordinates: 2°30′S 44°30′W / 2.5°S 44.5°W / -2.5; -44.5
Approximate paleocoordinates9°24′S 19°18′W / 9.4°S 19.3°W / -9.4; -19.3
Region Maranhão
Country Brazil
ExtentSão Luís-Grajaú Basin
Type section
Named forAlcântara (city)
Named byRossetti & Truckenbrodt
Year defined1997
Alcântara Formation is located in Brazil
Alcântara Formation
Alcântara Formation (Brazil)

The Alcântara Formation is a geological formation in northeastern Brazil whose strata date back to the Cenomanian of the Late Cretaceous.[1]

Fossil content

Dinosaurs

Dinosaurs
Genus Species Location Stratigraphic position Material Notes Images
Oxalaia[2] O. quilombensis Laje do Coringa, Cajual Island Cenomanian Fused premaxillae; isolated and incomplete left maxilla A spinosaurid Oxalaia quilombensis by PaleoGeek 2018.jpg

Crurotarsans

Crocodylomorphs
Genus Species Location Stratigraphic position Material Notes Images
Coringasuchus[3] C. anisodontis Laje do Coringa, Cajual Island Early Cenomanian Partial right lower jaw (dentary) Possibly a notosuchian

Squamates

Snakes
Genus Species Location Stratigraphic position Material Notes Images
Seismophis[4] S. septentrionalis Laje do Coringa, Cajual Island Cenomanian Vertebrae A snake

Fish

Fishes
Genus Species Location Stratigraphic position Material Notes Images
Equinoxiodus E. alcantarensis Laje do Coringa, Cajual Island Early Cenomanian A dipnoiform: 1 complete and 8 incomplete tooth plates [5]
Atlanticopristis A. equatorialis Falésia do Sismito, Cajual Island Early Cenomanian A sclerorhynchoid: 14 specimens (two complete) [6]
Mawsonia M. gigas Laje do Coringa, Cajual Island Early Cenomanian A coelacanthiform [7] Mawsonia sp.jpg

References

  1. ^ Rossetti, D.F.; Truckenbrodt, W. (1997). "Revisão estratigráfica para os depósitos do Albiano-Terciário Inferior (?) na Bacia de São Luís (MA), Norte do Brasil". Boletim do Museu Paraense Emílio Goeldi. 9: 29–41.
  2. ^ Kellner, Alexander W.A.; Azevedeo, Sergio A.K.; Machado, Elaine B.; Carvalho, Luciana B.; Henriques, Deise D.R. (2011). "A new dinosaur (Theropoda, Spinosauridae) from the Cretaceous (Cenomanian) Alcântara Formation, Cajual Island, Brazil" (PDF). Anais da Academia Brasileira de Ciências. 83 (1): 99–108. doi:10.1590/S0001-37652011000100006. ISSN 0001-3765.
  3. ^ Kellner, A.W.A.; Pinheiro, A.E.P.; Azevedo, S.A.K.; Henriques, D.D.R.; de Carvalho, L.B.; Oliveira, G.R. (2009). "A new crocodyliform from the Alcântara Formation (Cenomanian), Cajual Island, Brazil". Zootaxa. 2030: 49–58.
  4. ^ Hsiou, A. S.; Albino, A. M.; Medeiros, M. A.; Santos, R. A. B. (2013). "The oldest Brazilian snakes from the early Late Cretaceous (Cenomanian)". Acta Palaeontologica Polonica. 59 (3): 635–642. doi:10.4202/app.2012.0091.
  5. ^ Toledo, C.E.; Sousa, E.P.; Medeiros, M.A.; Bertini, R.J. (2011). "A new genus of dipnoiformes from the Cretaceous of Brazil". Anais da Academia Brasileira de Ciências. 83 (4): 1181–1192. doi:10.1590/s0001-37652011000400006.
  6. ^ Pereira, A.A.; Medeiros, M.A. (2008). "A new sclerorhynchiform (Elasmobranchii) from the middle Cretaceous of Brazil". Revista Brasileira de Paleontologia. 11 (3): 207–212. doi:10.4072/rbp.2008.3.07.
  7. ^ Medeiros, M.A., Carvalho, M.S.S., Silva, M.A.M., Pereira, A.A., Araujo, M.N., Ferreira, N.N., Vilas Bôas, I., 2011. O senhor dos rios: Mawsonia gigas (Mawsoniidae) do Cenomaniano do Maranhão, Brasil. In: Carvalho, I.S., Srivastava, N.K., Strohschoen, J.O., Lana, C.C. (Eds.), Paleontologia: Cenários de Vida, Vol. 4. Interciência, Rio de Janeiro, pp. 575-583.