The Jagua Formation is a

Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the ...

(middle to late Oxfordian) 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 ...

in the Sierra de los Órganos and Sierra del Rosario mountain ranges in

Pinar del Río Province Pinar del Río is one of the provinces of Cuba. It is at the western end of the island of Cuba. Geography The Pinar del Río province is Cuba's westernmost province and contains one of Cuba's three main mountain ranges, the Cordillera de Guanig ...

, western Cuba. Plesiosaur, pliosaur,

pterosaur Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the Order (biology), order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cre ...

,Barrett et al., 2008 metriorhynchid,

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked ...

and

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

remains are among the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s that have been recovered from its strata.

Description

The formation comprises marine

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especia ...

s and

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...

s. The thick Jagua Vieja Member consists of black shales and horizontally laminated marly micritic to biomicritic limestones. The latter contains

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an a ...

concretion A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular ...

s which the fossils are found in. The formation overlies the San Cayetano Formation and is overlain by the

Guasasa Formation The Guasasa Formation is a geologic formation in Cuba. It is Tithonian to Early Valanginian in age and contains fossils of ammonites. Description It primarily consists of limestone. See also * List of fossiliferous stratigraphic units in C ...

. The bedding direction is steeply dipping towards the northwest.

Fossil content

Vertebrate paleofauna

Other fossils

*'' Favreina'' *'' Globochaete'' * '' Gryphaea mexicana'' - Pan de Azúcar Mb. * '' Lepidotes gloriae'' * '' Liostrea mairei'' * '' L. sandalina'' - Zacarías Mb. * '' Nanogyra (Nanogyra) nana'' - Zacarías Mb. * ''

Ostrea broughtoni ''Ostrea'' is a genus of edible oysters, marine bivalve mollusks in the family Ostreidae, the oysters. Fossil records This genus is very ancient. It is known in the fossil records from the Permian to the Quaternary (age range: from 259 to ...

'' - Zacarías Mb.Mogote La Mina
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cre ...

.org * '' Plicatula cf. weymouthiana'' - Zacarías Mb. * '' Voltzia palmeri'' * '' Perisphinctes sp.''Viñales
at

.org

References

Bibliography

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