# Cerro Barcino Formation

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.
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

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.

### 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. | Tyrannotitan chubutensis Genyodectes serus |
| Genyodectes | G. serus | Cerro Castaño | partial snout | A possible ceratosaurid. | Tyrannotitan chubutensis Genyodectes serus |
| "Megalosaurus" | "M." inexpectatus | Bayo Overo | teeth | Indeterminate abelisaurid originally described as a species of Megalosaurus | Tyrannotitan chubutensis Genyodectes serus |
| Tyrannotitan | T. chubutensis | Cerro Castaño | two partial skeletons and teeth | A giant giganotosaurin carcharodontosaurid. | Tyrannotitan chubutensis Genyodectes serus |