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Capistrano Formation
The Capistrano Formation is a geologic formation in coastal southern Orange County, California. It preserves fossils dating back to the late Miocene to early Pliocene, with the Oso Member representing a near-shore environment. Fifty-nine species and varieties of foraminifera are recognized from the Capistrano Formation alongside a diverse array of marine mammals including up to five species of walrus. Geography The Capistrano Formation, named for the town of San Juan Capistrano, is located in southern California, specifically the northern extent of the Peninsular Ranges, which stretch from the Los Angeles Basin to Baja California. It crops out along the coast from Dana Point to San Clemente, and inland for seven miles. Geology and Stratigraphy The Capistrano Formation is a heterogenous marine formation that can be differentiated into two distinct but adjacent units. One of these units is the Oso Member, which is composed of arkosic sandstone and preserves a nearshore environ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 (geology), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles Basin
The Los Angeles Basin is a sedimentary Structural basin, basin located in Southern California, in a region known as the Peninsular Ranges. The basin is also connected to an wikt:anomalous, anomalous group of east–west trending chains of mountains collectively known as the Transverse Ranges. The present basin is a coastal lowland area, whose floor is marked by elongate low ridges and groups of hills that is located on the edge of the Pacific plate. The Los Angeles Basin, along with the Santa Barbara Channel, the Oxnard Plain, Ventura Basin, the San Fernando Valley, and the San Gabriel Valley, San Gabriel Basin, lies within the greater Southern California region. The majority of the jurisdictional land area of the city of Los Angeles physically lies within this basin. On the north, northeast, and east, the lowland Drainage basin, basin is bound by the Santa Monica Mountains and Puente, Elysian, and Repetto hills. To the southeast, the basin is bordered by the Santa Ana Mountains a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otodus
''Otodus'' is an extinct, cosmopolitan genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name ''Otodus'' comes from Ancient Greek (, meaning "ear") and (, meaning "tooth") – thus, "ear-shaped tooth". Description All species are known from their fossilized teeth, and four of them (''O. obliquus'', ''O. auriculatus'', ''O. angustidens'' and ''O. megalodon'') are also known from their fossilized vertebral centra. Like other elasmobranchs, the skeleton of ''Otodus'' was composed of cartilage and not bone, resulting in relatively few preserved skeletal structures appearing within the fossil record. The teeth of this shark are large with triangular crown, smooth cutting edges, and visible cusps on the roots. Some ''Otodus'' teeth also show signs of evolving serrations. Size estimation The fossils of ''Otodus'' sharks indicate that they were very large macro-predatory sharks. The largest known teeth of ''O. obliquus'' measure about in height. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myliobatis
''Myliobatis'' is a genus of eagle rays in the family (biology), family Myliobatidae. Description ''Myliobatis'' species can reach a width up to about . Their bodies consist of a rhomboidal disc, wider than long, with one dorsal fin. The head is broad and short, with eyes and spiracles on the sides. The tail is slender, with one or two large spines at the base, without tail fin. The teeth are arranged in the lower and upper jaws in flat tooth plates called pavement teeth, each consisting of about seven series of plates, which are used to crush clam shells and crustaceans. Biology ''Myliobatis'' species are Ovoviviparity, ovoviviparous. Their gestation lasts about six months, and a female produces four to seven embryos. ''Myliobatis'' species mainly feed on molluscs, bottom-living crustaceans, and small fishes. Habitat ''Myliobatis'' species live in warm, shallow waters. Adults prefer sandy shores, while juveniles can usually be encountered offshore. Species Extant species Curr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmopolitodus Hastalis (fossil Shark Tooth) (Tertiary; Probably From The Chesapeake Bay Region, USA) 3
''Cosmopolitodus'' is an extinct genus of mackerel shark that lived between thirty and one million years ago during the late Oligocene to the Early Pleistocene epochs. Its type species is ''Cosmopolitodus hastalis'', the broad-tooth mako (other common names include the extinct giant mako and broad-tooth white shark). In 2021, ''Isurus planus'' was reassigned to the genus, and thus became the second species ''C. planus''. However, some researchers still consider both species of ''Cosmopolitodus'' as species of ''Carcharodon''. Its teeth can reach lengths up to 3.5 in (7.5 cm) and are found worldwide. It is believed to be an ancestor to the great white shark, an argument supported by the transitional species ''Carcharodon hubbelli'', but as of 2021, no phylogenetic analyses have been done for proof. Taxonomy Etymology ''Cosmopolitodus'' is derived from the Ancient Greek κοσμοπολίτης "''kosmopolítēs''" meaning "citizen of the world" and ὀδών "''odṓn''" me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmopolitodus Hastalis
''Cosmopolitodus'' is an extinct genus of Lamnidae, mackerel shark that lived between thirty and one million years ago during the late Oligocene to the Early Pleistocene Epoch, epochs. Its type species is ''Cosmopolitodus hastalis'', the broad-tooth mako (other common names include the extinct giant mako and broad-tooth white shark). In 2021, ''Isurus planus'' was reassigned to the genus, and thus became the second species ''C. planus''. However, some researchers still consider both species of ''Cosmopolitodus'' as species of ''Carcharodon''. Its shark tooth, teeth can reach lengths up to 3.5 in (7.5 cm) and are found worldwide. It is believed to be an ancestor to the great white shark, an argument supported by the transitional species ''Carcharodon hubbelli'', but as of 2021, no Phylogenetics, phylogenetic analyses have been done for proof. Taxonomy Etymology ''Cosmopolitodus'' is derived from the Ancient Greek κοσμοπολίτης "''kosmopolítēs''" meaning "citize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmopolitodus
''Cosmopolitodus'' is an extinct genus of mackerel shark that lived between thirty and one million years ago during the late Oligocene to the Early Pleistocene epochs. Its type species is ''Cosmopolitodus hastalis'', the broad-tooth mako (other common names include the extinct giant mako and broad-tooth white shark). In 2021, ''Isurus planus'' was reassigned to the genus, and thus became the second species ''C. planus''. However, some researchers still consider both species of ''Cosmopolitodus'' as species of '' Carcharodon''. Its teeth can reach lengths up to 3.5 in (7.5 cm) and are found worldwide. It is believed to be an ancestor to the great white shark, an argument supported by the transitional species '' Carcharodon hubbelli'', but as of 2021, no phylogenetic analyses have been done for proof. Taxonomy Etymology ''Cosmopolitodus'' is derived from the Ancient Greek κοσμοπολίτης "''kosmopolítēs''" meaning "citizen of the world" and ὀδών "''odṓn''" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supralittoral Zone
The supralittoral zone, also known as the splash zone, spray zone or the supratidal zone, sometimes also referred to as the white zone, is the area above the spring high tide line, on coastlines and estuaries, that is regularly splashed, but not submerged by ocean water. Seawater penetrates these elevated areas only during storms with high tides.Thurman et al., p. 512. Organisms here must cope also with exposure to air, fresh water from rain, cold, heat and predation by land animals and seabirds. At the top of this area, patches of dark lichens can appear as crusts on rocks. Some types of periwinkles, Neritidae and detritus feeding Isopoda commonly inhabit the lower supralittoral.Yip and Madl See also *Littoral zone * Sublittoral zone Notes References * Thurman H.V. and Trujillo A.P. 1993.''Essentials of Oceanography''.Upper Saddle River, NJ:Prentice Hall * Yip, Maricela and Madl, Pierre (1999''Littoral''University of Salzburg The University of Salzburg (, ), also known as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathyal Zone
The bathypelagic zone or bathyal zone (from Greek βαθύς (bathýs), deep) is the part of the open ocean that extends from a depth of below the ocean surface. It lies between the mesopelagic above and the abyssopelagic below. The bathypelagic is also known as the midnight zone because of the lack of sunlight; this feature does not allow for photosynthesis-driven primary production, preventing growth of phytoplankton or aquatic plants. Although larger by volume than the photic zone, human knowledge of the bathypelagic zone remains limited by ability to explore the deep ocean. Physical characteristics The bathypelagic zone is characterized by a nearly constant temperature of approximately and a salinity range of 33-35 g/kg. This region has little to no light because sunlight does not reach this deep in the ocean and bioluminescence is limited. The hydrostatic pressure in this zone ranges from 100-400 atmospheres (atm) due to the increase of 1 atm for every 10 m depth. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminifers
Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell biology), ectoplasm for catching food and other uses; and commonly an external shell (called a "Test (biology), test") of diverse forms and materials. Tests of chitin (found in some simple genera, and ''Textularia'' in particular) are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment (i.e., are benthos, benthic, with different sized species playing a role within the macrobenthos, meiobenthos, and Benthos, microbenthos), while a smaller number float in the water column at various depths (i.e., are planktonic), which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been id ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemphillian
The Hemphillian North American Stage on the geologic timescale is a North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered to overlap the Tortonian age of the Late Miocene and Zanclean age of the Early Pliocene. The Hemphillian is preceded by the Clarendonian and followed by the Blancan The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years BP, a period of . [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility. Although its permeability and porosity is relatively low, siltstone is sometimes a tight gas reservoir rock, an unconventional reservoir for natural gas that requires hydraulic fracturing for economic gas production. Siltstone was prized in ancient Egypt for manufacturing statuary and cosmetic palettes. The siltstone quarried at Wadi Hammamat was a hard, fine-grained siltstone that resisted flaking and was almost ideal for such uses. Description There is not complete agreement on the definition of siltstone. One definition is that siltstone is mudrock (clastic sedimentary rock containing at least 50% clay and silt) in which at least 2/3 of the clay and silt fraction is composed of silt-sized particles. Silt is defined as grains 2–62 μm in diam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
