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Apón Formation
The Apón Formation is a geological formation in northwestern Venezuela (Maracaibo Basin) and northern Colombia (La Guajira),García González et al., 2010 whose thick-bedded limestone interbedded with subordinate amounts of dark gray calcareous shale and sandy shale strata date back to the Early Cretaceous ( Late Aptian epoch). Pterosaur remains of Ornithocheiridae indet. (= ?Anhangueridae indet.) are among the fossils that have been recovered from the formation.Barrett et al., 2008, p.84 Fossil content The following fossils, among others, have been found in the Apón Formation at Toas island: '' Spiroculina sp.'', '' Orbitolina concava'', '' Gryphaeostrea'', '' Amphidonte (Ceratostreon) boussingaulti'', '' Ostrea sp.'', '' Amphitriscoelus waringi'', '' Requienia sp.'', '' Parahoplites sp.'', '' Cheloniceras sp.'', '' Quinqueloculina sp.'', '' Triloculina sp.'', [...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] |
Ornithocheiridae
Ornithocheiridae (or ornithocheirids, meaning "bird hands") is a group of pterosaurs within the suborder Pterodactyloidea. These pterosaurs were among the last to possess teeth. Members that belong to this group lived from the Early to Late Cretaceous periods (Valanginian to Turonian stages), around 140 to 90 million years ago. Ornithocheirids are generally infamous for having an enormously controversial and very confusing taxonomy. Although agreements that these animals were related, and therefore similar to istiodactylids and pteranodontians, there is still no virtual consensus over the exact content and interrelationships of this group. Ornithocheirids were the most successful pterosaurs during their reign, they were also the largest pterosaurs before the appearance of the azhdarchids such as ''Quetzalcoatlus''. Ornithocheirids were excellent fish hunters, they used various flight techniques to catch their prey, and they are also capable of flying great distances without fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triloculina
''Triloculina'' is a genus of foraminifera in the order Miliolida, included in the Quinqueloculininae. The test is three, chambers each a half coil in length. Early chambers, at least in the microspheric generation, in quinqueloculinan arrangement, later becoming triloculine with successive chambers added in planes 120 degrees apart. Only the final three chambers are visible externally. The aperture is terminal, at the end of the final chamber, with a bifid tooth in adult forms. As with the entire order, the test is composed of imperforate, porcelaneous calcite. The Pliocene to Recent '' Cruciloculina'' is very similar, except for having a different aperture, and is a likely derivative. References * Joseph A. Cushman, 1950 Foraminifera, their classification and economic use (4th ed) Harvard University Press, Cambridge Mass. * Alfred R. Loeblich Jr Alfred R. Loeblich Jr (1914–1994) was an American micropaleontologist. He was married to Helen Niña Tappan Loeblich a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinqueloculina
''Quinqueloculina'' is a genus of foraminifera in the family Miliolidae. As with all miliolids the test of ''Quinqueloculina'' is composed of imperforate, porcelaneous calcite, often giving them a yellowish tint. As with the Miliolidae, the chambers are arranged in various planes, with two chambers per whorl. In ''Quinqueloculins'' the chambers are in planes set 72 degrees apart, but successive chambers are in planes separated by 144 degrees. The name ''Quinqueloculina'' comes from ''quinque'', the Latin for five. In ''Quinqueloculina'' five chambers are exposed to view on the outside, although the earlier three are sandwiched between the later two, one on one side, two on the other. Chambers are generally long and tubular, normally without integral floors, that function made by the underlying chamber. Some 30 or more species of ''Quinqueloculina'' have been named. ''Quinqueloculina'' is found in abundance around the coasts of the UK. High concentrations of one species of '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Requienia (bivalve)
''Requienia'' is an extinct genus of fossil saltwater clam, a marine bivalve molluscs in the order Hippuritida, family Requieniidae. These rudists lived in the Cretaceous period, from the Valanginian age (136.4–140.2) to the Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campani ... age (70.6–83.5 mya). They were stationary intermediate-level suspension feeders. Distribution This genus occurs in the Cretaceous of Albania (collection), Croatia, France, Germany, Hungary, Iraq, Italy, Mexico, Oman, Portugal, Serbia and Montenegro, Spain, Switzerland, Turkey, Ukraine, United States, Venezuela; Jurassic of Hungary. Species *''Requienia ammonia'' *''Requienia migliorinii'' *''Requienia renevieri'' References External links Universal Biological IndexerPaleobiology Databas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ostrea
''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 0.0 million years ago). Fossil shells of these molluscs can be found all over the world. Genus ''Ostrea'' includes about 150 extinct species. History At least one species within this genus, ''Ostrea lurida'', has been recovered in archaeological excavations along the Central California coast of the Pacific Ocean, demonstrating it was a marine taxon exploited by the Native American Chumash people as a food source. Species Species in the genus ''Ostrea'' include: * † ''Ostrea albertensis'' Russell & Landes, 1937 * ''Ostrea algoensis'' G. B. Sowerby II, 1871 *''Ostrea angasi'' G.B. Sowerby II, 1871 * ''Ostrea angelica'' Rochebrune, 1895 * † ''Ostrea angusta'' Deshayes, 1824 * † ''Ostrea anomialis'' Lamarck, 1819 * † ''Ostrea antarct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbitolina Concava
''Orbitolina'' is an extinct genus of foraminifera belonging to the order Textulariida and family Orbitolinidae. Fossils of this genus are widely found in beds deposited in the Tethys Ocean ranging from Aptian (early Cretaceous)) to Cenomanian (early Late Cretaceous) in age. It has been used as a shallow carbonate platform facies In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formatio ... marker and as a Cretaceous index fossil. The test of the organism has the shape of a cone, with the proloculus (initial chamber) at the apex of the cone and increasingly large cuplike chambers forming the remainder of the test. Each chamber is further subdivided by numerous partitions. References Globothalamea {{Foraminifera-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
