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.
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.Rauhut et al., 2003
The Cerro Barcino Formation is subdivided into several subunits (members). 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.
Fossil content Possible rebbachisaurid remains are known from the La Paloma Member.
Lepidosaurs (Kaikaifilusaurus minimus) and testudinatans (Chubutemys copelloi and Prochelidella cerrobarcinae) are also discovered from this formation.
Crurotarsans Crocodylomorphs Genus Species Location Stratigraphic position Material Notes Images Barcinosuchus 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 C. insignis Bayo Overo Two partial skeletons A basal somphospondylan Patagotitan 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 Genyodectes G. serus Cerro Castaño Partial snout A possible ceratosaurid "Megalosaurus" "M." inexpectatus Bayo Overo Teeth An indeterminate abelisaurid originally described as a species of MegalosaurusWeishampel et al., 2004, pp.563-570 Tyrannotitan 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
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