Echinoderm Families

picture info	Echinoderm Families An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7,000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest entirely marine phylum. The first definitive echinoderms appeared near the start of the Cambrian. The echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs, and limbs; in some cases, they can undergo complete regeneration from a single limb. Geolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Asteroidea Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at below the surface. Starfish are marine invertebrates. They typically have a central disc and usually five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Rhombifera The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian. Eocrinoids were a paraphyletic group that may have been ancestral to six other classes: Rhombifera, Diploporita, Coronoidea, Blastoidea, Parablastoidea, and Paracrinoidea. They may also be the progenitors of the cystoids, who are believed to be ancestral to modern crinoids. The earliest genera had a short holdfast and irregularly structured plates. Later forms had a fully developed stalk with regular rows of plates. They were benthic suspension feeders, with five ambulacra on the upper surface, surrounding the mouth and extending into a number of narrow arms. An unusual Ordovician form was the conical '' Bolboporites'' with its single brachiole.Rozhnov, S.V. and Kushlina, V.B. 1994. Interpretation of new data on ''Bolboporites'' Pan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Brittle Star Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to in length on the largest specimens. The Ophiuroidea contain two large clades, Ophiurida (brittle stars) and Euryalida (basket stars). Over 2,000 species of brittle stars live today. More than 1,200 of these species are found in deep waters, greater than 200 m deep. Range The ophiuroids diverged in the Early Ordovician, about 500 million years ago. Ophiuroids can be found today in all of the major marine provinces, from the poles to the tropics. Basket stars are usually confined to the deeper parts of this range; Ophiuroids are known even from abyssal (>6,000 m) depths. However, brittle stars are also common members of reef communities, where t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at below the surface. Starfish are marine invertebrates. They typically have a central disc and usually five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Radial Symmetry Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, take the face of a human being which has a plane of symmetry down its centre, or a pine cone with a clear symmetrical spiral pattern. Internal features can also show symmetry, for example the tubes in the human body (responsible for transporting gases, nutrients, and waste products) which are cylindrical and have several planes of symmetry. Biological symmetry can be thought of as a balanced distribution of duplicate body parts or shapes within the body of an organism. Importantly, unlike in mathematics, symmetry in biology is always approximate. For example, plant leaves – while considered symmetrical – rarely match up exactly when folded in half. Symmetry is one class of patterns in nature whereby there is near-repetition of the pattern element, either by reflection or rotation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature for algae, fungi, and plants accepts the terms as equivalent. Depending on definitions, the animal kingdom Animalia contains about 31 phyla, the plant kingdom Plantae contains about 14 phyla, and the fungus kingdom Fungi contains about 8 phyla. Current research in phylogenetics is uncovering the relationships between phyla, which are contained in larger clades, like Ecdysozoa and Embryophyta. General description The term phylum was coined in 1866 by Ernst Haeckel from the Greek (, "race, stock"), related to (, "tribe, clan"). Haeckel noted that species constantly evolved into new species that seemed to retain few consistent features among themselves and therefore few features that distinguished them as a group ("a self-contained unity" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Paracrinoid Paracrinoidea is an extinct class of blastozoan echinoderms. They lived in shallow seas during the Early Ordovician through the Early Silurian. While blastozoans are usually characterized by types of respiratory structures present, it is not clear what types of respiratory structures paracrinoids likely had. Despite the taxon's name, the paracrinoids are not closely related to crinoids. Paracrinoids are characterized by a mouth with two to five feeding arms arranged asymmetrically, or somewhat bisymmetrically. They have a U-shaped gut, and their anus is located next to the mouth. They have irregularly shaped bodies (theca), and a stem, superficially similar to crinoids, and may have used the stem to attach themselves to a substrate, although some reconstructions show them partially buried in sediment.Fossil Invertebrates, 1987, Boardman, Richard S., Cheetham, Alan H., and Rowell, Albert J., editors, pp. 580-1. Blackwell Scientific Publications. Only 13 to 15 genera are known. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Otto Jaekel Otto Max Johannes Jaekel (21 February 1863 – 6 March 1929) was a German paleontologist and geologist. Biography Jaekel was born in Neusalz (Nowa Sól), Prussian Silesia, the son of a builder and the youngest of seven children. He studied at the ''Ritterakademie'' in Liegnitz (Legnica). After graduating in 1883, he came to study geology and paleontology under Ferdinand Roemer in Breslau (Wrocław) until 1885. Karl von Zittel awarded a PhD to Jaekel in Munich in 1886. Between 1887 and 1889, Jaekel was an assistant of E.W. Benecke at the Geologisch-Paläontologisches Institut in Straßburg, where he received his Habilitation. He worked at the Friedrich-Wilhelms-Universität Berlin and at the Geologisch-Paläontologisches Museum (a combined post) from 1894. Jaekel was considered as an ordinary professor of geology at the University of Vienna in 1903, but this was blocked by intrigue. Between 1906 and 1928, Jaekel was a professor at the University of Greifswald, where he fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Eocrinoidea The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian. Eocrinoids were a paraphyletic group that may have been ancestral to six other classes: Rhombifera, Diploporita, Coronoidea, Blastoidea, Parablastoidea, and Paracrinoidea. They may also be the progenitors of the cystoids, who are believed to be ancestral to modern crinoids. The earliest genera had a short holdfast and irregularly structured plates. Later forms had a fully developed stalk with regular rows of plates. They were benthic suspension feeders, with five ambulacra on the upper surface, surrounding the mouth and extending into a number of narrow arms. An unusual Ordovician form was the conical '' Bolboporites'' with its single brachiole.Rozhnov, S.V. and Kushlina, V.B. 1994. Interpretation of new data on ''Bolboporites'' Pande ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Blastozoa Blastozoa is a subphylum of extinct animals belonging to Phylum Echinodermata. This subphylum is characterized by the presence of specialized respiratory structures and brachiole plates used for feeding. This subphylum ranged from the Cambrian to the Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz .... References External linksHarvard: Subphylum Blastozoa Paleozoic echinoderms Cambrian echinoderms Silurian echinoderms Ordovician echinoderms Devonian echinoderms Permian echinoderms Animal subphyla {{paleo-echinoderm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Helicoplacoidea Helicoplacoidea is an extinct class within the Echinodermata. All known taxa were discovered in sediments dating back to the Cambrian.Fossilworks: Helicoplacoidea ''fossilworks.org''. Retrieved 2021-01-13. Description Helicoplacoid skeletons consist of small platelets arranged like those of asteroids , lacking fused skeletons as in echinoids Sea urchins () are spine (zoology), spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every dept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Ophiocistioidea The Ophiocistioidea is a class of extinct echinoderms from the Palaeozoic and early Mesozoic. Ophiocistioids had a flattened dome-shaped body encased in a solid test of calcareous plates, similar to that of a modern sea urchin. The mouth was at the apex of the dome, and surrounded by a set of five jaws. The animals apparently did not have an anus, but a madreporite was on the upper surface, surrounded by what appear to be genital pores for the release of gametes. Five ambulacra radiated outwards from the mouth across the upper surface, but did not extend onto the flat underside. Each had three unusually large tube feet at the margin of the dome. Unlike normal tube feet, these were covered in small bony scales, and therefore remain visible in fossils. See also List of echinodermata orders This List of echinoderm orders concerns the various classes and orders into which taxonomists categorize the roughly 7000 extant species as well as the extinct species of the exclusively m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]

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