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Takatika Grit
The Takatika Grit is a geologic formation in Chatham Islands, New Zealand. It preserves fossils dating back to the Paleocene period, although it also preserves disturbed and re-worked Maastrichtian and Campanian microfossils and tetrapod fossils. A 2017 study found that it dated to late Early to Mid Paleocene on the basis of dinoflagellates. It has been subdivided into two informal units, a lower phosphatic unit containing bones and nodular phosphatic layers, and an upper unit with abundant sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ... remains and siliceous microfossils. Description The two informal units are further subdivided into two units each, the lower is divided into the lower which consists of " poorly sorted, phosphatized grit with abundant phosphorite nodule ... [...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] |
Phosphorite
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxide (P2O5). Marketed phosphate rock is enriched ("beneficiated") to at least 28%, often more than 30% P2O5. This occurs through washing, screening, de-liming, magnetic separation or flotation. By comparison, the average phosphorus content of sedimentary rocks is less than 0.2%.Blatt, Harvey and Robert J. Tracy, ''Petrology'', Freeman, 1996, 2nd ed. pp. 345–349 The phosphate is present as fluorapatite Ca5(PO4)3F typically in cryptocrystalline masses (grain sizes < 1 μm) referred to as -sedimentary apatite deposits of uncertain origin. It is also present as |
Elasmosauridae
Elasmosauridae is an extinct family of plesiosaurs, often called elasmosaurs. They had the longest necks of the plesiosaurs and existed from the Hauterivian to the Maastrichtian stages of the Cretaceous, and represented one of the two groups of plesiosaurs present at the end of the Cretaceous alongside Polycotylidae. Their diet mainly consisted of crustaceans and molluscs. Description The earliest elasmosaurids were mid-sized, about . In the Late Cretaceous, elasmosaurids grew as large as , such as '' Styxosaurus'', ''Albertonectes'', and '' Thalassomedon''. Their necks were the longest of all the plesiosaurs, with anywhere between 32 and 76 (''Albertonectes'') cervical vertebrae. They weighed up to several tons. Classification Early three-family classification Though Cope had originally recognized ''Elasmosaurus'' as a plesiosaur, in an 1869 paper he placed it, with ''Cimoliasaurus'' and ''Crymocetus'', in a new order of sauropterygian reptiles. He named the group Streptos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edaphodon Kawai
''Edaphodon kawai'' was a prehistoric chimaeriform fish species belonging to the genus ''Edaphodon'', of which all the species are now extinct. ''Edaphodon kawai'' was a type of rabbitfish, a cartilaginous fish related to sharks and rays, and indeed, some rabbitfishes are still alive today. ''E. kawai'' is one of numerous ''Edaphodon'' species, but is the only one which has been discovered in the Southern Hemisphere, near New Zealand. Indeed, only a handful of other Chimaeroformes have been discovered in the Southern Hemisphere. They first appeared during the Devonian period around 415 to 360 million years ago, but the only known specimen of ''E. kawai'' has been dated to the Late Cretaceous at the height of the rabbitfish's reign. Its scientific name, ''kawai'', means "fish" in the language of the Moriori, a Pacific tribe who inhabited the islands. Description Like most prehistoric cartilaginous fishes, ''E. kawai'' is known from a few fragmentary remains, including teeth an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edaphodon
''Edaphodon'' was a fish genus of the family Callorhinchidae (sometimes assigned to Edaphodontidae). As a member of the Chimaeriformes, ''Edaphodon'' was a type of rabbitfish, a cartilaginous fish related to sharks and rays. The genus appeared in the Aptian age of the Lower Cretaceous and vanished in the Pliocene. It was most prominent during the Late Cretaceous. Many ''Edaphodon'' species were found in the Northern Hemisphere, but species from the Southern Hemisphere are also known (e.g., ''E. kawai'' from New Zealand and ''E. snowhillensis'' from Antarctica). Description Like most other chimaeriforms, ''Edaphodon'' is known mainly from poorly preserved specimens because its skeleton was made of cartilage. So, in most cases, only tooth plates and fin spines have been preserved, and they are also often dissociated. Like other chimaeriforms, it fed using six pairs of tooth plates—one pair on the lower jaw (mandibular) and two pairs on the upper (vomerine and palatine), which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydoselachus
''Chlamydoselachus'' is a genus of sharks and the sole extant member of the family (biology), family Chlamydoselachidae, in the order (biology), order Hexanchiformes. It contains two extant and several extinct species. The most widely known species still surviving is the frilled shark (''Chlamydoselachus anguineus''). It is known as a living fossil, along with ''Chlamydoselachus africana'', also known as the southern African frilled shark, which is only found along coastal areas of South Africa. The only two extant species of this genus are deep-sea creatures which are typically weakened in areas closer to the surface. Species * ''Southern African frilled shark, Chlamydoselachus africana'' David A. Ebert, Ebert & Leonard Compagno, Compagno, 2009 (southern African frilled shark) * ''Frilled shark, Chlamydoselachus anguineus'' Samuel Garman, Garman, 1884 (frilled shark) * †''Chlamydoselachus bracheri'' Pfeil, 1983 * †''Chlamydoselachus fiedleri'' Pfeil, 1983 * †''Chlamydosela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillariophyceae
Bacillariophyceae is a group of pennate diatoms with a raphe (raphids). According to Ruggiero et al., 2015, the diatoms are treated as follows. This treatment largely reflects that used by Algaebase as at 2015, and is also reflected in the current (mid 2020) treatment used iDiatomBase the World Register of Marine Species (WoRMS) of which DiatomBase is a part, and the Catalogue of Life. This treatment is identical to that of Round et al., 1990, except that all diatoms are treated as a single class, Round et al.'s classes are reduced to subclasses, and the latter's original subclasses are omitted. It has 3 subclasses, '' Bacillariophycidae'', ''Coscinodiscophycidae'' and '' Fragilariophycidae'' Subclass Bacillariophycidae Contains the following orders; * Achnanthales (2k) * Bacillariales (3k) * Cymbellales (4k) * Dictyoneidales (17) * Eunotiales (2k) * Lyrellales (38) * Mastogloiales (825) * Naviculales (18k) * Rhopalodiales (527) * Surirellales (2k) * Thalassiophysales (1k) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexactinellid
Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma. Some experts believe glass sponges are thlongest-lived animals on earth these scientists tentatively estimate a maximum age of up to 15,000 years. Biology Glass sponges are relatively uncommon and are mostly found at depths from below the sea level. Although the species '' Oopsacas minuta'' has been found in shallow water, others have been found much deeper. They are found in all oceans of the world, although they are particularly common in Antarctic and Northern Pacific waters. They are more-or-less cup-shaped animals, ranging from in height, with sturdy lattice-like internal skeletons made up of fused spicules of silica. The body is relatively symmetrical, with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dactylocalycidae
Dactylocalycidae is a family of sponges belonging to the order Lychniscosida. Genera: * '' Dactylocalyx'' Stutchbury, 1841 * '' Exanthesis'' Regnard, 1925 * '' Iphiteon'' Bowerbank, 1869 * '' Moretiella'' Breistroffer, 1949 * '' Ophrystoma'' Zittel, 1878 * '' Paraplocia'' Pomel, 1872 References {{Taxonbar, from=Q4125611 Sponges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponge Spicule
Spicules are structural elements found in most sponges. The meshing of many spicules serves as the sponge's skeleton and thus it provides structural support and potentially defense against predators. Sponge spicules are made of calcium carbonate or silica. Large spicules visible to the naked eye are referred to as megascleres, while smaller, microscopic ones are termed microscleres. The composition, size, and shape of spicules are major characters in sponge systematics and taxonomy. Overview Sponges are a species-rich clade of the earliest-diverging (most basal) animals. They are distributed globally, with diverse ecologies and functions, and a record spanning at least the entire Phanerozoic. Most sponges produce skeletons formed by spicules, structural elements that develop in a wide variety of sizes and three dimensional shapes. Among the four sub-clades of Porifera, three (Demospongiae, Hexactinellida, and Homoscleromorpha) produce skeletons of amorphous silica and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
