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Heteractinida
Heteractinida is an extinct Evolutionary grade, grade of Paleozoic (Cambrian–Permian) Sponge, sponges, sometimes used as a Class (biology), class or Order (biology), order. They are most commonly considered Paraphyly, paraphyletic with respect to Calcarea (calcareous sponges), though some studies instead argue that they are paraphyletic relative to Hexactinellid, Hexactinellida (glass sponges). Heteractinids can be distinguished by their six-pronged (snowflake-shaped) Sponge spicule, spicules, whose symmetry historically suggested a relationship with the triradial calcarean sponges. The sponge-like Cambrian Hetairacyathidae may be related to heteractinids, though most instead consider hetairacyathids to be closer to Archaeocyatha, archaeocyaths and Radiocyatha, radiocyaths.''Treatise on Invertebrate Paleontology'' Part E, Revised. Porifera, Volumes 4 & 5: Hypercalcified Porifera, Paleozoic Stromatoporoidea & Archaeocyatha, liii + 1223 p., 665 figs., 2015, availablhere . Subgrou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocyatha
Radiocyatha is an extinct group of sponge-like animals which lived in the early to mid-Cambrian Period (Tommotian to Toyonian). Details They were very similar to Archaeocyatha, archaeocyath sponges, with a cup-shaped calcareous body up to 20 cm (7.9 inches) in height. One major difference is that the radiocyath skeleton is not composed of tiny calcite grains, but rather large aragonite plates, known as nesasters. Nesasters are star-shaped, with up to 20 radiating spokes in a flat plane. The outer wall of the cup has radial rods directed inwards. ''Uranosphaera'' is a simple single-walled radiocyath, while the hetairacyathids bear an additional nested wall layer, akin to archaeocyaths.''Treatise on Invertebrate Paleontology'' Part E, Revised. Porifera, Volumes 4 & 5: Hypercalcified Porifera, Paleozoic Stromatoporoidea & Archaeocyatha, liii + 1223 p., 665 figs., 2015, availablhere . Radiocyaths reached their maximum abundance in the Atdabanian and Botomian, contributing towards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hetairacyathidae
Radiocyatha is an extinct group of sponge-like animals which lived in the early to mid-Cambrian Period (Tommotian to Toyonian). Details They were very similar to archaeocyath sponges, with a cup-shaped calcareous body up to 20 cm (7.9 inches) in height. One major difference is that the radiocyath skeleton is not composed of tiny calcite grains, but rather large aragonite plates, known as nesasters. Nesasters are star-shaped, with up to 20 radiating spokes in a flat plane. The outer wall of the cup has radial rods directed inwards. ''Uranosphaera'' is a simple single-walled radiocyath, while the hetairacyathids bear an additional nested wall layer, akin to archaeocyaths.''Treatise on Invertebrate Paleontology'' Part E, Revised. Porifera, Volumes 4 & 5: Hypercalcified Porifera, Paleozoic Stromatoporoidea & Archaeocyatha, liii + 1223 p., 665 figs., 2015, availablhere . Radiocyaths reached their maximum abundance in the Atdabanian and Botomian, contributing towards the biomass o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eiffeliidae
Eiffeliidae is an extinct family of 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 ...s. Genera The following genera are placed in the family: * †'' Astraeoconus'' Rietschel, 1968 * †'' Chilcaia'' Carrera, 1994 * †'' Eiffelia'' Walcott, 1920 (synonyms: ''Lenastella'' Missarzhevsky ''in'' Missarzhevsky & Mambetov, 1981; ''Actinoites'' Duan, 1984; ''Niphadus'' Duan, 1984) * †'' Eiffelospongia'' Rigby & Collins, 2004 * †'' Gondekia'' Rigby, 1991 * †'' Petaloptyon'' Raymond, 1931 (synonyms: ''Canistrumella'' Rigby, 1986) * †'' Toquimiella'' Rigby, 1967 * †'' Zangerlispongia'' Rigby & Nitecki, 1975 References Prehistoric sponge families {{paleo-sponge-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Grade
A grade is a taxon united by a level of morphological or physiological complexity. The term was coined by British biologist Julian Huxley, to contrast with clade, a strictly phylogenetic unit. Definition An evolutionary grade is a group of species united by morphological or physiological traits, that has given rise to another group that has major differences from the ancestral condition, and is thus not considered part of the ancestral group, while still having enough similarities that we can group them under the same clade. The ancestral group will not be phylogenetically complete (i.e. will not form a clade), so will represent a paraphyletic taxon. In order to fully understand evolutionary grades, one must first get a better understanding of Phylogenetics, defined as "''In biology, is the study of the evolutionary history and relationships among individuals or groups of organisms (e.g. species, or populations). These relationships are discovered through phylogenetic i ... [...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] |
Archaeocyatha
Archaeocyatha (or archaeocyathids 'ancient cups') is a taxon of extinct, sessile, reef-building marine sponges that lived in warm tropical and subtropical waters during the Cambrian Period. It is believed that the centre of the Archaeocyatha origin is now located in East Siberia, where they are first known from the beginning of the Tommotian Age of the Cambrian, 525 million years ago ( mya). In other regions of the world, they appeared much later, during the Atdabanian, and quickly diversified into over a hundred families. They became the planet's very first reef-building animals and are an index fossil for the Lower Cambrian worldwide. Preservation The remains of Archaeocyatha are mostly preserved as carbonate structures in a limestone matrix. This means that the fossils cannot be chemically or mechanically isolated, save for some specimens that have already eroded out of their matrices, and their morphology has to be determined from thin cuts of the stone in which they ... [...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] |
Springer Science+Business Media
Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing. Originally founded in 1842 in Berlin, it expanded internationally in the 1960s, and through mergers in the 1990s and a sale to venture capitalists it fused with Wolters Kluwer and eventually became part of Springer Nature in 2015. Springer has major offices in Berlin, Heidelberg, Dordrecht, and New York City. History Julius Springer founded Springer-Verlag in Berlin in 1842 and his son Ferdinand Springer grew it from a small firm of 4 employees into Germany's then second largest academic publisher with 65 staff in 1872.Chronology ". Springer Science+Business Media. In 1964, Springer expanded its business internationally, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
