The Cerro Barcino Formation (also known as the Gorro Frigio Formation) is a geological formation in South America whose strata span the mid-late Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 period. Dinosaur remains are among the fossils that have been recovered from the formation.

The Cerro Barcino Formation is the upper unit of the Chubut Group, which also includes the older Los Adobes Formation. Both formations cover a vast area in Chubut Province

Chubut Province

Chubut a province in the southern part of Argentina situated between the 42nd parallel south and the 46th parallel south , the Andes range separating Argentina from Chile, and the Atlantic ocean...

, Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. 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:

• 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 are likely Albian

Albian

The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...

 to Campanian

Campanian

The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...

 in age (112 to 83 million years ago), while the La Paloma may date to the latest Hauterivian

Hauterivian

The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous epoch or a stage in the Lower Cretaceous series. It spans the time between 136.4 ± 2 Ma and 130 ± 1.5 Ma...

 (130ma).

Fauna

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

Crurotarsans

Crocodylomorphs Crocodylomorpha The Crocodylomorpha are an important group of archosaurs that include the crocodilians and their extinct relatives.During Mesozoic and early Tertiary times the Crocodylomorpha were far more diverse than they are now. Triassic forms were small, lightly built, active terrestrial animals. These were...  of the Adamantina Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Barcinosuchus Barcinosuchus Barcinosuchus is an extinct genus of carnivorous metasuchian from the early Cretaceous period. It is a peirosaurid which lived during the early Cretaceous period in what is now Chubut Province, Argentina. It is known from the holotype MPEF-PV 3095, which consists of skull, mandible, and...	B. gradilis	Near El Escorial El Escorial The Royal Seat of San Lorenzo de El Escorial is a historical residence of the king of Spain, in the town of San Lorenzo de El Escorial, about 45 kilometres northwest of the capital, Madrid, in Spain. It is one of the Spanish royal sites and functions as a monastery, royal palace, museum, and...  village, Chubut Province Chubut Province Chubut a province in the southern part of Argentina situated between the 42nd parallel south and the 46th parallel south , the Andes range separating Argentina from Chile, and the Atlantic ocean... .	Cerro Castaño Member.	"Skull, mandible, and postcranial remains."	A peirosaurid Peirosauridae Peirosauridae is a Gondwanan family of mesoeucrocodylians that lived during the Cretaceous period. It was a clade of terrestrial crocodyliforms that evolved a rather dog-like form, and were terrestrial carnivores. It was phylogenetically defined in 2004 as the most recent common ancestor of... . The first crocodyliform from the Chubut Group.

Dinosaurs

Dinosaur Dinosaur Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of... s of the Cerro Barcino Formation
Genus	Species	Presence	Material	Notes	Images
Chubutisaurus Chubutisaurus Chubutisaurus is a genus of dinosaur from the Early Cretaceous Period. It lived in South America. It is classified as a sauropod, specifically one of the titanosaurs. The type species, C. insignis, was described by del Corro in 1975. Its fossils were found in the Cerro Barcino Formation, Albian...	Chubutisaurus insignis	Present in the Bayo Overo Member.	"[Two] partial skeletons including most limb elements and caudal vertebrae."	A titanosaur Titanosaur Titanosaurs were a diverse group of sauropod dinosaurs, which included Saltasaurus and Isisaurus. It includes some of the heaviest creatures ever to walk the earth, such as Argentinosaurus and Paralititan — which some believe have weighed up to 100 tonnes... .
Genyodectes Genyodectes Genyodectes is a genus of ceratosaurian theropod dinosaur from the Lower Cretaceous of South America. The holotype material was collected from the Cañadón Grande, Departamento Paso de Indios in the Chubut Province of Argentina and consists of an incomplete snout, including the premaxillae,...	Genyodectes serus	Present in the Cerro Castaño Member.	"Premaxillae, partial dentaries."	A possible ceratosaurid Ceratosauridae Ceratosauridae is a family of theropod dinosaurs belonging to the infraorder Ceratosauria. Its type genus, Ceratosaurus, was first found in Jurassic rocks from North America. Ceratosauridae is made up of Ceratosaurus, found in North America, Tanzania, and Portugal, and Genyodectes, from the Late... .
"Megalosaurus"	"Megalosaurus" inexpectatus			Indeterminate remains originally described as a species of Megalosaurus Megalosaurus Megalosaurus is a genus of large meat-eating theropod dinosaurs of the Middle Jurassic period of Europe... .
Tyrannotitan Tyrannotitan Tyrannotitan is a genus of huge bipedal carnivorous dinosaur of the carcharodontosaurid family from the Aptian stage of the early Cretaceous period, discovered in Argentina. It is closely related to other giant predators like Giganotosaurus and Carcharodontosaurus...	Tyrannotitan chubutensis	Present in the Cerro Castaño Member.		A carcharodontosaurid Carcharodontosauridae Carcharodontosaurids were a group of carnivorous theropod dinosaurs. In 1931 Ernst Stromer named Carcharodontosauridae as a family, in modern paleontology this name indicates a clade within Carnosauria... .