Cuscatlán Formation

	Cuscatlán Formation The Cuscatlán Formation is a geologic formation in El Salvador. It preserves fossils dating back to the Pliocene to Middle Pleistocene (Blancan to Irvingtonian) period. Fossil content * ''Borophagus hilli'' * '' Meizonyx salvadorensis'' * '' Megalonyx obtusidens'' * '' cf. Arctotherium sp.''''Arctotherium'' 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 * '' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Formation (stratigraphy) 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 W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Arctotherium ''Arctotherium'' ("''bear beast''") is an extinct genus of the Pleistocene short-faced bears endemic to Central and South America. ''Arctotherium'' migrated from North America to South America during the Great American Interchange, following the formation of the Isthmus of Panama during the late Pliocene. The genus consists of one early giant form, ''A. angustidens'', and several succeeding smaller species, which were within the size range of modern bears. ''Arctotherium'' was adapted to open and mixed habitat. They are genetically closer to the spectacled bear (''Tremarctos ornatus''), than to ''Arctodus'' of North America, implying the two extinct forms evolved large size in a convergent manner, perhaps to facilitate dominating other carnivores in the competition for the biggest carcasses. Evolution Tremarctinae ''Arctotherium'' is part of the Tremarctinae subfamily of bears, otherwise known as the short faced bears, which also includes ''Arctodus'' (North American shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Fossiliferous Stratigraphic Units Of North America 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 in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Neogene North America The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago (Mya) to the beginning of the present Quaternary Period Mya. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first humans (''Homo habilis'') appeared in Africa near the end of the period. Some continental movements took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the warm ocean currents from the Pacific to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Geology Of El Salvador The geology of El Salvador is underlain by rocks dating to the Paleozoic. Prior to the Pennsylvanian, sediments deposited and were intensely deformed, intruded by granite rocks and metamorphosed. Northern Central America took shape during uplift in the Triassic, large than its current area and extending east to the Nicaragua Rise. The Cayman Ridge and Bartlet Trough formed from longitudinal faults at the crest of the uplift. Deformation in the Cretaceous brought granite intrusions, particularly in what is now Nicaragua. Much of the terrain and coastline of the country is defined by volcanoes and volcanic deposits produced from the subduction of the Cocos Plate. On the surface, rocks in El Salvador primarily date to the Pliocene and early Pleistocene and are typically volcanic. Some of the oldest surface exposures are in the Metapan area, with pre-Mesozoic monzonite together with Cretaceous marine limestone, overlain by Paleogene volcanic and terrestrial sedimentary rocks. The 650 fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]