Bajo Barreal Formation

The Bajo Barreal Formation is a geological formation in the Golfo San Jorge Basin of Chubut and Santa Cruz, Argentina whose strata date back to the Middle Cenomanian to Late Turonian. The formation was first described by Teruggi & Rossetto in 1963.[1] The sandstones, claystones, mudstones, conglomerates and tuff were deposited in a fluvial environment.[2] The upper part of formation is laterally equivalent to the Yacimiento El Trébol and Meseta Espinosa Formation and the lower part to the Laguna Palacios, Cañadón Seco and Comodoro Rivadavia Formations. The Bajo Barreal Formation is a reservoir rock in the Golfo San Jorge Basin.[3]

Bajo Barreal Formation
Stratigraphic range: Mid Cenomanian-Late Turonian
~97–90 Ma
TypeGeological formation
Unit ofChubut Group
UnderliesLago Colhué Huapí Formation
OverliesCastillo Formation
OtherClaystone, mudstone, conglomerate, tuff
Coordinates45°18′S 69°36′W / 45.3°S 69.6°W / -45.3; -69.6Coordinates: 45°18′S 69°36′W / 45.3°S 69.6°W / -45.3; -69.6
Approximate paleocoordinates51°36′S 46°42′W / 51.6°S 46.7°W / -51.6; -46.7
RegionChubut, Santa Cruz
Country Argentina
ExtentGolfo San Jorge Basin
Type section
Named byTeruggi & Rossetto
Year defined1963
Bajo Barreal Formation is located in Argentina
Bajo Barreal Formation
Bajo Barreal Formation (Argentina)

Vertebrate paleofaunaEdit


Dinosaur remains are among the fossils that have been recovered from the formation.[4] Dinosaur remains include the abelisaurid theropod Xenotarsosaurus bonapartei, as well as indeterminate teeth belonging to carcharodontosaurids and dromaeosaurids.[5]

Dinosaurs reported from the Bajo Barreal Formation
Genus Species Stratigraphic position Material Notes Images
Aniksosaurus[6] A. darwini[6] Lower A basal coelurosaur
Campylodoniscus[6][7] C. ameghinoi[6] Lower Maxilla with seven teeth.[8]
Clasmodosaurus[8] C. spatula[6] Jaw with seven teeth[8] A sauropod
Drusilasaura[9] D. deseadensis Upper "four dorsal vertebrae, one sacral vertebra, six caudal vertebrae, left scapula, dorsal rib fragments, two haemapophyses and indeterminate fragments" A titanosaur belonging to Lognkosauria
Epachthosaurus[6] E. sciuttoi[6] Lower "Vertebrae [and] partial illium."[10]
Notohypsilophodon[6] N. comodorensis[6] Lower "Vertebrae, partial fore- and hindlimb"[11]
Sarmientosaurus[12] S. musacchioi Lower A skull A lithostrotian titanosaur
Xenotarsosaurus[6] X. bonapartei[6] Lower A vertebra and a nearly complete hind limb[13]
Other fossils

Other fossils found in the formation include:[14][15][16]

See alsoEdit


  1. ^ Casal et al., 2016, p.55
  2. ^ Bajo Barreal Formation at
  3. ^ Sywan, 2001, p.131
  4. ^ 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.
  5. ^ Casal, G., Candeiro, C.R.A., Martínez, R., Ivany, E., and Ibiricu, L. (2009). "Dientes de Theropoda (Dinosauria: Saurischia) de la Formación Bajo Barreal, Cretácico Superior, Provincia del Chubut, Argentina." Geobios, doi:10.1016/j.geobios.2009.03.002.
  6. ^ a b c d e f g h i j k "63.2 Provincia de Chubut, Argentina; 2. Bajo Barreal Formation," in Weishampel, et al. (2004). Page 602.
  7. ^ Haubold, H. & Kuhn, O., 1961, Lebensbilder und Evolution fossiler Saurier, Amphibien und Reptilien, Wittenberg : Ziemsen
  8. ^ a b c Huene, F. von, 1929, "Los Saurisquios y Ornitisquios del Cretaceo Argentino", Anales del Museo de La Plata, 3(2): 82-83
  9. ^ César Navarrete, Gabriel Casal and Rubén Martínez (2011). "Drusilasaura deseadensis gen. et sp. nov., a new titanosaur (Dinosauria-Sauropoda), of the Bajo Barreal Formation, Upper Cretaceous of north of Santa Cruz, Argentina". Revista Brasileira de Paleontologia 14 (1): 1-14. doi:10.4072/rbp.2011.1.01.
  10. ^ "Table 13.1," in Weishampel, et al. (2004). Page 268.
  11. ^ "Table 18.1," in Weishampel, et al. (2004). Page 395.
  12. ^ Martínez et al., 2016
  13. ^ "Table 3.1," in Weishampel, et al. (2004). Page 49.
  14. ^ Casal, 2016, p.58
  15. ^ Estancia Laguna Palacios "2005 Quarry" at
  16. ^ 6 km north of Estancia "Ocho Hermanos" at


Further readingEdit

  • G. Casal and L. Ibiricu. 2010. Materiales asignables a Epachthosaurus Powell, 1990 (Sauropoda: Titanosauria), de la Formación Bajo Barreal, Cretácico Superior, Chubut, Argentina [Materials assignable to Epachthosaurus Powell, 1990 (Sauropoda: Titanosauria), from the Bajo Barreal Formation, Upper Cretaceous, Chubut, Argentina]. Revista Brasileira de Paleontologia 13(3):247-256
  • L. M. Ibiricu, G. A. Casal, R. D. Martinez, M. C. Lamanna, M. Luna and L. Salgado. 2013. Katepensaurus goicoecheai, gen. et sp. nov., a Late Cretaceous rebbachisaurid (Sauropoda, Diplodocoidea) from central Patagonia, Argentina. Journal of Vertebrate Paleontology 33(6):1351-1366
  • L. M. Ibiricu, G. A. Casal, M. C. Lamanna, R. D. Martínez, J. D. Harris and K. J. Lacovara. 2012. The southernmost records of Rebbachisauridae (Sauropoda: Diplodocoidea), from early Late Cretaceous deposits in central Patagonia. Cretaceous Research 34:220-232
  • R. D. Martínez, F. E. Novas, and A. Ambrosio. 2004. Abelisaurid remains (Theropoda, Ceratosauria) from southern Patagonia. Actas I del Congreso Ltinoamericano de Paleontología de Vertebrados. Ameghiniana 41(4):577-585
  • R. D. Martínez and F. E. Novas. 1997. Un nuevo tetanuro (Dinosauria: Theropoda) de la Formación Bajo Barreal (Cretácico Superior), Patagonia [A new tetanuran (Dinosauria: Theropoda) from the Bajo Barreal Formation (Upper Cretaceous), Patagonia]. Ameghiniana 34(4):538
  • R. D. Martínez, A. Maure, M. Oliva and M. Luna. 1993. Un maxilar de Theropoda (Abelisauria) de la Formación Bajo Barreal, Cretacico Tardio, Chubut, Argentina [A theropod (Abelisauria) maxilla from the Bajo Barreal Formation, Late Cretaceous, Chubut, Argentina]. Ameghiniana 30(1):109-110
  • J. C. Sciutto and R. D. Martínez. 1994. Un nuevo yacimiento fosilífero de la Formación Bajo Barreal (Cretacico Tardio) y su fauna de saurópodos [A new fossiliferous locality in the Bajo Barreal Formation (Late Cretaceous) and its sauropod fauna]. Naturalia Patagonica, Ciencias de la Tierra 2:27-47