The Dos Bocas Formation is a

Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...

, about 26 to 24 Ma, (

Deseadan The Deseadan ( es, Deseadense) age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It fo ...

in the SALMA classification) geologic

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary ...

of the

Progreso Basin Progreso or Progresso ( Spanish, Portuguese and Italian for " Progress") may refer to: Places Angola * Progresso, Belas, Luanda, Angola Belize *Progresso, Belize, village in the Corozal District Bolivia * Progreso Airport Guatemala * El P ...

in southwestern Ecuador.

Description

The formation comprises moderately-sorted, fine to medium sandstones with angular quartz- feldspathic clasts. Conspicuous rounded green grains are probably glauconite, but berthierine cannot be dismissed. The matrix is micritic and volcanogenic, possibly bentonitic. The formation was deposited in an

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

to mid shelf environment. Fossils of sharks, turtles and the tropical ''

Urkudelphis ''Urkudelphis'' is an extinct genus of cetacean. The type species, ''Urkudelphis chawpipacha'', was described in 2017 based on fossils found in the Dos Bocas Formation of Ecuador.Montañita/Olón
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org

Fossil content

The formation has provided fossils of: * ''

Carcharocles angustidens ''Otodus angustidens'' is a species of prehistoric megatoothed sharks in the genus '' Otodus'', which lived during the Oligocene and Miocene epochs about 33 to 22 million years ago. This shark is related to another extinct megatoothed shark, '' ...

'' * '' Urkudelphis chawpipacha''Tanaka et al., 2017 * Chelonioidea indet.

Description

Fossil content

See also

References

Bibliography

Further reading