Bajo Barreal Formation

Bajo Barreal Formation
Stratigraphic range: Mid Cenomanian-Late Turonian ~97–90  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Chubut Group
Underlies	Lago Colhué Huapí Formation
Overlies	Castillo Formation
Lithology
Primary	Sandstone
Other	Claystone, mudstone, conglomerate, tuff
Location
Coordinates	45°18′S69°36′W / 45.3°S 69.6°W / -45.3; -69.6
Approximate paleocoordinates	51°36′S46°42′W / 51.6°S 46.7°W / -51.6; -46.7
Region	Chubut, Santa Cruz
Country	Argentina
Extent	Golfo San Jorge Basin
Type section
Named by	Teruggi & Rossetto
Year defined	1963
Bajo Barreal Formation (Argentina)

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]

Vertebrate paleofauna

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

Indeterminate abelisauroids and titanosaurs have been recovered from the formation.

Ornithopods

Ornithopods reported from the Bajo Barreal Formation
Genus	Species	Stratigraphic position	Material	Notes	Images
Notohypsilophodon [4]	N. comodorensis [4]	Lower	"Vertebrae, partial fore- and hindlimb" [5]	An elasmarian ornithopod.

Sauropods

Sauropods reported from the Bajo Barreal Formation
Genus	Species	Stratigraphic position	Material	Notes	Images
Andesaurus [1]	A. sp. [1]	Lower		The most basal member of Titanosauria
Campylodoniscus [4] [6]	C. ameghinoi [4]	Lower	Maxilla with seven teeth. [7]
Drusilasaura [8]	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 [4]	E. sciuttoi [4]	Lower	"Vertebrae [and] partial illium." [9]
Katepensaurus	K. goicoecheai	Lower	Partial skeleton	A rebbachisaurid
Rebbachisauridae [10]	Indeterminate	Lower	Dorsal vertebra	Different from Katepensaurus.
Sarmientosaurus [11]	S. musacchioi	Lower	A skull	A lithostrotian titanosaur with a skull similar to Brachiosaurus

Theropods

Theropods reported from the Bajo Barreal Formation
Genus	Species	Stratigraphic position	Material	Notes	Images
Abelisauridae [1]	Indeterminate [1]	Lower	Maxilla	Possibly distinct from Xenotarsosaurus. Estimated to be 6.21 metres (20.4 ft) long, larger than Xenotarsosaurus. [12]
Abelisauridae [13]		Lower	partial skeleton	Different from all other comparable abelisaurids, but can't be compared with Xenotarsosaurus.
Aniksosaurus [4]	A. darwini [4]	Lower		A basal coelurosaur
Megaraptoridae [14]	Indeterminate	Upper part of lower Lowermost part of upper	Two partial skeletons
Xenotarsosaurus [4]	X. bonapartei [4]	Lower	A vertebra and a nearly complete hind limb [15]	An abelisaur.

Other fossils

Other fossils found in the formation include: ^{[16] [17] [18]}

• Bonapartemys bajobarrealis
• Prochelidella argentinae
• Anura indet.
• Chelonia indet.
• Crocodylia indet.
• Pterosauria indet.

See also

• List of dinosaur-bearing rock formations
• Mata Amarilla Formation, contemporaneous formation of the Austral Basin
• Lisandro Formation, contemporaneous formation of the Neuquén Basin

References

1. Casal et al., 2016, p.55
2. Bajo Barreal Formation at Fossilworks.org
3. Sywan, 2001, p.131
4. "63.2 Provincia de Chubut, Argentina; 2. Bajo Barreal Formation," in Weishampel, et al. (2004). Page 602.
5. "Table 18.1," in Weishampel, et al. (2004). Page 395.
6. Haubold, H. & Kuhn, O., 1961, Lebensbilder und Evolution fossiler Saurier, Amphibien und Reptilien, Wittenberg : Ziemsen
7. Huene, F. von, 1929, "Los Saurisquios y Ornitisquios del Cretaceo Argentino", Anales del Museo de La Plata, 3(2): 82-83
8. 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.
9. "Table 13.1," in Weishampel, et al. (2004). Page 268.
10. Ibiricu, Lucio M.; Casal, Gabriel A.; Martínez, Rubén D.; Alvarez, Bruno N.; Poropat, Stephen F. (2020). "New materials and an overview of Cretaceous vertebrates from the Chubut Group of the Golfo San Jorge Basin, central Patagonia, Argentina". Journal of South American Earth Sciences. 98: 102460. Bibcode:2020JSAES..9802460I. doi:10.1016/j.jsames.2019.102460. S2CID   212808289.
11. Martínez et al., 2016
12. Grillo, Orlando Nelson; Delcourt, Rafael (2017-01-01). "Allometry and body length of abelisauroid theropods: Pycnonemosaurus nevesi is the new king" . Cretaceous Research. 69: 71–89. Bibcode:2017CrRes..69...71G. doi:10.1016/j.cretres.2016.09.001. ISSN   0195-6671.
13. Lamanna, Matthew C. (2012). "A new abelisaurid (Theropoda: Ceratosauria) skeleton from the Upper Cretaceous Bajo Barreal Formation of Chubut Province, Argentina". Journal of Vertebrate Paleontology. 32 (Supplement 2): 124. Archived from the original on 2019-09-15. Retrieved 2020-11-30.
14. Lamanna, Matthew C.; Casal, Gabriel A.; Martínez, Rubén D. F.; Ibiricu, Lucio M. (2020-11-30). "Megaraptorid (Theropoda: Tetanurae) Partial Skeletons from the Upper Cretaceous Bajo Barreal Formation of Central Patagonia, Argentina: Implications for the Evolution of Large Body Size in Gondwanan MegaraptoranS". Annals of Carnegie Museum. 86 (3): 255–294. doi:10.2992/007.086.0302. S2CID   229355207.
15. "Table 3.1," in Weishampel, et al. (2004). Page 49.
16. Casal, 2016, p.58
17. Estancia Laguna Palacios "2005 Quarry" at Fossilworks.org
18. 6 km north of Estancia "Ocho Hermanos" at Fossilworks.org

Bibliography

• Casal, Gabriel A.; Martínez, Ruben D.; Luna, Marcelo; Ibiricu, Lucio M. (2016), "Ordenamiento y caracterización faunística del Cretácico Superior del Grupo Chubut, Cuenca del Golfo San Jorge, Argentina" (PDF), Revista Brasileira de Paleontologia , 19: 53–70, doi:10.4072/rbp.2016.1.05 , retrieved 2019-02-16
• Martínez, Rubén D.F.; Lamanna, Matthew C.; Novas, Fernando E.; Ridgely, Ryan C.; Casal, Gabriel A.; Martínez, Javier E.; Vita, Javier R.; Witmer, Lawrence M. (2016), "A Basal Lithostrotian Titanosaur (Dinosauria: Sauropoda) with a Complete Skull: Implications for the Evolution and Paleobiology of Titanosauria", PLoS ONE , 11 (4): e0151661, Bibcode:2016PLoSO..1151661M, doi: 10.1371/journal.pone.0151661 , hdl: 11336/17517 , PMC   4846048 , PMID   27115989
• Sylwan, Claudio A (2001), "Geology of the Golfo San Jorge Basin, Argentina", Journal of Iberian Geology , 27: 123–157, retrieved 2018-09-04
• Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), The Dinosauria, 2nd edition, Berkeley: University of California Press, pp. 1–880, ISBN   0-520-24209-2 , retrieved 2019-02-21

Further reading

• 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