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Jagua Formation
The Jagua Formation is a Late Jurassic (middle to late Oxfordian) geologic formation in the Sierra de los Órganos and Sierra del Rosario mountain ranges in Pinar del Río Province, western Cuba. Plesiosaur, pliosaur, pterosaur,Barrett et al., 2008 metriorhynchid, turtle and dinosaur remains are among the fossils that have been recovered from its strata. Description The formation comprises marine shales and limestones. The thick Jagua Vieja Member consists of black shales and horizontally laminated marly micritic to biomicritic limestones. The latter contains calcareous concretions which the fossils are found in. The formation overlies the San Cayetano Formation and is overlain by the Guasasa Formation. 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'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallardosaurus
''Gallardosaurus'' is a genus of pliosaurid plesiosaur from the Caribbean seaway. It contains the single species ''Gallardosaurus iturraldei''. ''Gallardosaurus'' was found in middle-late Oxfordian-age (Late Jurassic) rocks of the Jagua Formation of western Cuba.''Gallardosaurus'' at .org ''Gallardosaurus'' is believed to be evolutionarily connected to '''', a pliosaurid commonly found in the Oxfordian-aged sediment. History and etymology [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropterygia
Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became extinct at the end of that period. The plesiosaurs would continue to diversify until the end of the Mesozoic. Sauropterygians are united by a radical adaptation of their pectoral girdle, adapted to support powerful flipper strokes. Some later sauropterygians, such as the pliosaurs, developed a similar mechanism in their pelvis. Uniquely among reptiles, sauropterygians moved their tail vertically like modern cetaceans and sirenians. Origins and evolution The earliest sauropterygians appeared about 247 million years ago (Ma), at the start of the Middle Triassic: the first definite sauropterygian with exact stratigraphic datum lies within the Spathian division of the Olenekian era in South China. Early examples were small (around 60 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptoclidus
''Cryptoclidus'' ( ) is a genus of plesiosaur reptile from the Middle Jurassic Period (geology), period of England, France, and Cuba. Discovery ''Cryptoclidus'' was a plesiosaur whose specimens include adult and juvenile skeletons, and remains which have been found in various degrees of preservation in England, Northern France, Russia, and South America. Its name, meaning "hidden clavicles", refer to its small, practically invisible clavicles buried in its front limb girdle. The type species was initially described as ''Plesiosaurus eurymerus'' by Phillips (1871). The specific name "wide femur" refers to the forelimb, which was mistaken for a hindlimb at the time. Fossils of ''Cryptoclidus'' have been found in the Oxford Clay of Cambridgeshire, England. The dubious species ''Cryptoclidus beaugrandi'' is known from Kimmeridgian-age deposits in Boulogne-sur-Mer, France. ''Cryptoclidus vignalensis'', which is now considered undiagnostic, hails from the Jagua Formation of western ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhamphorhynchid
Rhamphorhynchidae is a group of early pterosaurs named after ''Rhamphorhynchus'', that lived in the Late Jurassic. The family Rhamphorhynchidae was named in 1870 by Harry Govier Seeley.Seeley, H.G. (1870). "The Orithosauria: An Elementary Study of the Bones of Pterodactyles." Cambridge, 135 p. Members of the group possess no more than 11 pairs of teeth in the rostrum, a deltopectoral crest that is constricted at the base but expanded at the distal end, and a bent phalange on the fifth toe. Rhamphorhynchidae traditionally contains two subfamilies: the Rhamphorhynchinae and the Scaphognathinae. While not recovered as distinct clades by all analyses, there do appear to be traits uniting members of each group. Rhamphorhynchines are more common, were lightly built, and had jaws ending in pointed tips that contained more teeth, which are often procumbent (pointed forward). Scaphognathines are comparatively quite rare, were more robust skeletally, and had shorter wing proportions. The br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cacibupteryx
''Cacibupteryx'' is a genus of rhamphorhynchid pterosaur from the middle-late Oxfordian-age Upper Jurassic Jagua Formation of Pinar del Río, Cuba. The genus was named in 2004 by Zulma Gasparini, Marta Fernández and Marcelo de la Fuente. The type species is ''Cacibupteryx caribensis''. The genus name is derived from ''Cacibu'', the "Lord of the Sky" in Taíno and Greek ''pteryx'', "wing". The specific name refers to the Caribbean, ''Caribe'' in Spanish. The genus is based on holotype IGO-V 208, a partial but well-preserved uncrushed skull — missing the tip of the snout, teeth, and lower jaws — and fragmentary left wing: the distal end of the ulna, fragments of the radius, and the first and fourth phalanx of the wing finger. The partial skull is seventeen centimeters long (6.7 inches), is preserved in three dimensions, and has a broad roof. The wingspan and length were not estimated by the describers, but it was indicated to be a relatively large form. The describe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 shapes also occur. The word 'concretion' is derived from the Latin "(act of) compacting, condensing, congealing, uniting", itself from ''con'' meaning 'together' and ''crescere'' meaning "to grow". Concretions form within layers of sedimentary strata that have already been deposited. They usually form early in the burial history of the sediment, before the rest of the sediment is hardened into rock. This concretionary cement often makes the concretion harder and more resistant to weathering than the host stratum. There is an important distinction to draw between concretions and nodules. Concretions are formed from mineral precipitation around some kind of nucleus while a nodule is a replacement body. Descriptions dating from the 18th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 adjectival term applied to anatomical structures which are made primarily of calcium carbonate, in animals such as gastropods, i.e., snails, specifically about such structures as the operculum, the clausilium, and the love dart. The term also applies to the calcium carbonate tests of often more or less microscopic Foraminifera. Not all tests are calcareous; diatoms and radiolaria have siliceous tests. The molluscs are calcareous, as are calcareous sponges ( Porifera), that have spicules which are made of calcium carbonate. In botany ''Calcareous grassland'' is a form of grassland characteristic of soils containing much calcium carbonate from underlying chalk or limestone rock. In medicine The term is used in pathology, for example i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrite
Micrite is a limestone constituent formed of calcareous particles ranging in diameter up to four μm formed by the recrystallization of lime mud. Flügel, Erik, ''Microfacies of Carbonate Rocks: Analysis, Interpretation and Application,'' Springer, pp 74-94, 2004 The term was coined in 1959 by Robert Folk for his carbonate rock classification system. Micrite is derived from MICRocrystalline calcITE. In the Folk classification micrite is a carbonate rock dominated by fine-grained calcite. Carbonate rocks that contain fine-grained calcite in addition to allochems are named ''intramicrite'', ''oomicrite'', ''biomicrite'' or ''pelmicrite'' under the Folk classification depending on the dominant allochem. Micrite is lime mud, carbonate of mud grade. Micrite as a component of carbonate rocks can occur as a matrix, as micrite envelopes around allochems or as peloids Peloids are allochems that are composed of micrite, irrespective of size, shape, or origin. The two primary types of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marl
Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part of the cliffs of Dover, and the Channel Tunnel follows these marl layers between France and the United Kingdom. Marl is also a common sediment in post-glacial lakes, such as the marl ponds of the northeastern United States. Marl has been used as a soil conditioner and neutralizing agent for acid soil and in the manufacture of cement. Description Marl or marlstone is a carbonate-rich mud or mudstone which contains variable amounts of clays and silt. The term was originally loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay and calcium carbonate, formed under freshwater conditions. These typically contain 35–65% clay and 65–35% carbonate. The te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black 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, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable bedding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
