Cerro Barcino Formation

Cerro Barcino Formation
Stratigraphic range: Hauterivian-Albian
~130–100 Ma
Type Geological formation
Unit of Chubut Group
Sub-units Puesto Manuel Arce
Bayo Overo
Las Plumas
Cerro Castaño
La Paloma
Underlies La Colonia, Paso del Sapo & Lefipán Formations
Overlies Los Adobes Formation
Lithology
Primary Mudstone, sandstone
Other Conglomerate, tuff
Location
Coordinates 43°48′S 68°36′W / 43.8°S 68.6°W / -43.8; -68.6Coordinates: 43°48′S 68°36′W / 43.8°S 68.6°W / -43.8; -68.6
Approximate paleocoordinates 44°42′S 35°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

The Cerro Barcino Formation (also known as the Gorro Frigio Formation) is a geological formation in South America whose strata span the Early Cretaceous. The top age for the formation has been estimated to be Albian.[1] Earlier estimates placed the formation until the Campanian.[2]

The formation was deposited in the Cañadón Asfalto Basin, a rift basin that started forming in the earliest Jurassic.[3] Dinosaur remains are among the fossils that have been recovered from the formation.[4]

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.[2]

The Cerro Barcino Formation is subdivided into several subunits ("members").[2] From oldest to youngest:

  • La Paloma
    • Characterized by arid plains interspersed with sand dunes
  • Cerro Castaño
    • A return to more humid, flood-plain conditions
  • Las Plumas
  • Bayo Overo
  • Puesto Manuel Arce

The final three members were estimated to range from Albian to Campanian age (112 to 83 million years ago), while the La Paloma dates to the latest Hauterivian (130 Ma).[2]

Fauna

Indeterminate abelisaurid remains.[4] Possible indeterminate carcharodontosaurid remains.[4] Indeterminate Titanosauria remains.[4] Also, an unnamed titanosauriform.[4]

Crurotarsans

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.
Crocodylomorphs of the Adamantina Formation
Genus Species Location Stratigraphic position Material Notes Images

Barcinosuchus[5]

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

Dinosaurs of the Cerro Barcino Formation
Genus Species Presence Material Notes Images

Chubutisaurus

Chubutisaurus insignis

Present in the Bayo Overo Member.

"[Two] partial skeletons including most limb elements and caudal vertebrae."[6]

A titanosaur.[4]
Genyodectes

Genyodectes

Genyodectes serus

Present in the Cerro Castaño Member.[7]

"Premaxillae, partial dentaries."[8]

A possible ceratosaurid.

"Megalosaurus"

"Megalosaurus" inexpectatus

Indeterminate remains originally described as a species of Megalosaurus.[4]

Patagotitan

Patagotitan mayorum

Tyrannotitan

Tyrannotitan chubutensis

Present in the Cerro Castaño Member.

A carcharodontosaurid.[9]

See also

References

  1. ↑ Figari et al., 2015, p.153
  2. 1 2 3 4 Rauhut, O.W.M., Cladera, G., Vickers-Rich, P. and Rich, T.H. (2003). "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
  3. ↑ Figari et al., 2015, p.142
  4. 1 2 3 4 5 6 7 Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 563-570. ISBN 0-520-24209-2.
  5. ↑ Juan Martín Leardi and Diego Pol (2009). "The first crocodyliform from the Chubut Group (Chubut Province, Argentina) and its phylogenetic position within basal Mesoeucrocodylia". Cretaceous Research. 30 (6): 1376–1386. doi:10.1016/j.cretres.2009.08.002.
  6. ↑ "Table 13.1," in Weishampel, et al. (2004). Page 268.
  7. ↑ Rauhut, O.W.M. (2004). Provenance and anatomy of Genyodectes serus, a large-toothed ceratosaur (Dinosauria: Theropoda) from Patagonia. Journal of Vertebrate Paleontology 24(4):894-902.
  8. ↑ "Table 3.1," in Weishampel, et al. (2004). Page 50.
  9. ↑ Novas, F. E.; S. de Valais; P. Vickers-Rich; T. Rich (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.

Bibliography

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