| Cerro Barcino Formation | |
| Type: | Geological formation |
| Age: | Aptian-Cenomanian ~ |
| Period: | Aptian |
| Prilithology: | Mudstone, sandstone |
| Otherlithology: | Conglomerate, tuff |
| Namedfor: | Cerro Barcino |
| Region: | Chubut Province |
| Country: | Argentina |
| Coordinates: | -43.8°N -68.6°W |
| Paleocoordinates: | -44.7°N -35.1°W |
| Unitof: | Chubut Group |
| Subunits: | Las Plumas Cerro Castaño Puesto La Paloma Bayo Overo |
| Underlies: | Puesto Manuel Arce Formation |
| Overlies: | Los Adobes Formation |
| Extent: | Cañadón Asfalto Basin |
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.[1]
The Cerro Barcino Formation is subdivided into several subunits (members).[1] From oldest to youngest:
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]
Indeterminate abelisaurid remains from the Puesto La Paloma Member. Possible rebbachisaurid remains are known from the La Paloma Member.
Lepidosaurs (Kaikaifilusaurus minimus and Priosphenodon minimus) and Testudinata (Chubutemys copelloi and Prochelidella cerrobarcinae) are also discovered from this formation.[2]
| Dinosaurs | |||||
|---|---|---|---|---|---|
| Genus | Species | Member | Material | Notes | Images |
| Chubutisaurus[4] | C. insignis | Bayo Overo | two partial skeletons | A basal somphospondylan | |
| Genyodectes[5] | G. serus | Cerro Castaño | partial snout | A possible ceratosaurid. | |
| Patagotitan[6] | P. mayorum | Cerro Castaño | partial skeleton and other elements | A huge lognkosaur. | |
| Tyrannotitan[7] | T. chubutensis | Cerro Castaño | two partial skeletons and teeth | A giant giganotosaurin carcharodontosaurid. | |
| "Megalosaurus" | "M." inexpectatus | Bayo Overo | teeth | Indeterminate abelisaurid originally described as a species of Megalosaurus[8] [9] | |
| Abelisauroidea | indeterminate | La Paloma member | Vertebrae | Very similar to the later and more large bodied abelisauroids from South America such as Carnotaurus.[10] | |