Cerro Barcino Formation

Cerro Barcino Formation
Stratigraphic range: Aptian-Cenomanian ~118–98  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Chubut Group
Sub-units	Las Plumas Cerro Castaño Puesto La Paloma Bayo Overo
Underlies	Puesto Manuel Arce Formation
Overlies	Los Adobes Formation
Lithology
Primary	Mudstone, sandstone
Other	Conglomerate, tuff
Location
Coordinates	43°48′S68°36′W / 43.8°S 68.6°W / -43.8; -68.6
Approximate paleocoordinates	44°42′S35°06′W / 44.7°S 35.1°W / -44.7; -35.1
Region	Chubut Province
Country	Argentina
Extent	Cañadón Asfalto Basin
Type section
Named for	Cerro Barcino
Cerro Barcino Formation (Argentina)

The Cerro Barcino Formation (also known as the Gorro Frigio Formation) is a geological formation in South America whose strata span the Early Cretaceous to the earliest Late Cretaceous. The top age for the formation has been estimated to be Cenomanian. Earlier estimates placed the formation until the Campanian. ^[1]

The formation was deposited in the Cañadón Asfalto Basin, a rift basin that started forming in the earliest Jurassic. Dinosaur remains are among the fossils that have been recovered from the formation.

The Cerro Barcino Formation is the second-youngest unit of the Chubut Group, which also includes the older Los Adobes Formation. Both formations cover a vast area in Chubut Province, Argentina. The two formations are distinguished by geological features suggesting a distinct change in climate, from a wetter, flood plain environment in the Los Adobes to a much more arid, desert-like environment in the Cerro Barcino. ^[1]

The Cerro Barcino Formation is subdivided into several subunits (members). ^[1] From oldest to youngest:

• Bayo Overo (Correlates with both the Puesto La Paloma and the Cerro Castaño members)
• Puesto La Paloma
  • Characterized by arid plains interspersed with sand dunes
• Cerro Castaño
  • A return to more humid, flood-plain conditions
• Las Plumas

The Puesto La Paloma Member dates from ~118-113 Ma, the Cerro Castaño Member dates from ~113-100.5 Ma, correlating with the Albian, and the Las Plumas Member dates from ~100.5-98 Ma. ^[2]

Fossil content

Indeterminate abelisaurid remains from the Puesto La Paloma Member. ^[1] Possible rebbachisaurid remains are known from the La Paloma Member. ^{[1] [2]}

Lepidosaurs ( Kaikaifilusaurus minimus and Priosphenodon minimus ) and Testudinata ( Chubutemys copelloi and Prochelidella cerrobarcinae ) are also discovered from this formation. ^[2]

Crurotarsans

Crocodylomorphs
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Barcinosuchus [3]	B. gradilis	Near El Escorial village, Chubut Province	Cerro Castaño Member	"Skull, mandible, and postcranial remains."	A peirosaurid. The first crocodyliform from the Chubut Group

Dinosaurs

Sauropods

Sauropods of the Cerro Barcino Formation
Genus	Species	Member	Material	Notes	Images
Chubutisaurus [4]	C. insignis	Bayo Overo	two partial skeletons	A basal somphospondylan
Patagotitan [5]	P. mayorum	Cerro Castaño	partial skeleton and other elements	A huge lognkosaur.

Theropods

Theropods of the Cerro Barcino Formation
Genus	Species	Member	Material	Notes	Images
Abelisauroidea	indeterminate	La Paloma member	Vertebrae	Very similar to the later and more large bodied abelisauroids from South America such as Carnotaurus. [6]	Tyrannotitan chubutensis Genyodectes serus
Genyodectes [7]	G. serus	Cerro Castaño	partial snout	A possible ceratosaurid.
"Megalosaurus"	"M." inexpectatus	Bayo Overo	teeth	Indeterminate abelisaurid originally described as a species of Megalosaurus [8] [9]
Tyrannotitan [10]	T. chubutensis	Cerro Castaño	two partial skeletons and teeth	A giant giganotosaurin carcharodontosaurid.

See also

• List of dinosaur-bearing rock formations
• La Amarga Formation, contemporaneous fossiliferous formation of the Neuquén Basin
• Lohan Cura Formation, contemporaneous fossiliferous formation of the Neuquén Basin
• Río Belgrano Formation, contemporaneous fossiliferous formation of the Austral Basin

References

1. Rauhut et al., 2003
2. Krause, J. Marcelo; Ramezani, Jahandar; Umazano, Aldo M.; Pol, Diego; Carballido, José L.; Sterli, Juliana; Puerta, Pablo; Cúneo, N. Rubén; Bellosi, Eduardo S. (2020-04-01). "High-resolution chronostratigraphy of the Cerro Barcino Formation (Patagonia): Paleobiologic implications for the mid-cretaceous dinosaur-rich fauna of South America" (PDF). Gondwana Research. 80: 33–49. Bibcode:2020GondR..80...33K. doi:10.1016/j.gr.2019.10.005. ISSN   1342-937X. S2CID   210265289.
3. Leardi, Juan Martín; Pol, Diego (2009-12-01). "The first crocodyliform from the Chubut Group (Chubut Province, Argentina) and its phylogenetic position within basal Mesoeucrocodylia" (PDF). Cretaceous Research. 30 (6): 1376–1386. Bibcode:2009CrRes..30.1376L. doi:10.1016/j.cretres.2009.08.002. hdl:11336/90736. ISSN   0195-6671.
4. Carballido, José L.; Pol, Diego; Cerda, Ignacio; Salgado, Leonardo (2011-02-10). "The osteology of Chubutisaurus insignis del Corro, 1975 (Dinosauria: Neosauropoda) from the 'middle' Cretaceous of central Patagonia, Argentina". Journal of Vertebrate Paleontology. 31 (1): 93–110. Bibcode:2011JVPal..31...93C. doi:10.1080/02724634.2011.539651. hdl: 11336/94194 . ISSN   0272-4634. S2CID   86055386.
5. Carballido, José L.; Pol, Diego; Otero, Alejandro; Cerda, Ignacio A.; Salgado, Leonardo; Garrido, Alberto C.; Ramezani, Jahandar; Cúneo, Néstor R.; Krause, Javier M. (2017-08-16). "A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs". Proceedings of the Royal Society B: Biological Sciences. 284 (1860). doi:10.1098/rspb.2017.1219. ISSN   0962-8452. PMC   5563814 . PMID   28794222.
6. Rauhut, Oliver W. M.; Cladera, Gerardo; Vickers-Rich, Patricia; Rich, Thomas H. (2003-10-01). "Dinosaur remains from the Lower Cretaceous of the Chubut Group, Argentina". Cretaceous Research. 24 (5): 487–497. doi:10.1016/S0195-6671(03)00067-3. ISSN   0195-6671.
7. Rauhut, Oliver W. M. (2004-12-10). "Provenance and anatomy of Genyodectes serus, a large-toothed ceratosaur (Dinosauria: Theropoda) from Patagonia". Journal of Vertebrate Paleontology. 24 (4): 894–902. doi:10.1671/0272-4634(2004)024[0894:PAAOGS]2.0.CO;2. ISSN   0272-4634. S2CID   131178611.
8. Weishampel et al., 2004, pp.563-570
9. Ezcurra, Martin Daniel; Novas, Fernando Emilio (2016). "Theropod dinosaurs from Argentina" (PDF). Contribuciones del MACN. ISSN   1666-5503.
10. Canale, Juan Ignacio; Novas, Fernando Emilio; Pol, Diego (2015-01-02). "Osteology and phylogenetic relationships of Tyrannotitan chubutensis Novas, de Valais, Vickers-Rich and Rich, 2005 (Theropoda: Carcharodontosauridae) from the Lower Cretaceous of Patagonia, Argentina" (PDF). Historical Biology. 27 (1): 1–32. Bibcode:2015HBio...27....1C. doi:10.1080/08912963.2013.861830. hdl:11336/17607. ISSN   0891-2963. S2CID   84583928.

Bibliography

• Figari, Eduardo G.; Scasso, Roberto A.; Cúneo, Rubén N.; Escapa, Ignacio (2015), "Estratigrafía y evolución geológica de la Cuenca de Cañadón Asfalto, Provincia del Chubut, Argentina" (PDF), Latin American Journal of Sedimentology and Basin Analysis , 22: 135–169, retrieved 2018-09-10
• Novas, F.E.; De Valais, S.; Vickers-Rich, P.; Rich, T. (2005), "A large Cretaceous theropod from Patagonia, Argentina, and the evolution of carcharodontosaurids", Naturwissenschaften , 92 (5): 226–230, Bibcode:2005NW.....92..226N, doi:10.1007/s00114-005-0623-3, PMID   15834691 , retrieved 2019-04-06 doi : 10.1007/s00114-005-0623-3 PMID   15834691 Bibcode : 2005NW.....92..226N
• Rauhut, O.W.M.; Cladera, G.; Vickers-Rich, P.; Rich, T.H. (2003), "Dinosaur remains from the Lower Cretaceous of the Chubut Group, Argentina" (PDF), Cretaceous Research , 24 (5): 487–497, Bibcode:2003CrRes..24..487R, doi:10.1016/S0195-6671(03)00067-3 , retrieved 2019-04-06 doi : 10.1016/S0195-6671(03)00067-3
• 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