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Antedon Bifida 01
''Antedon'' is a genus of free-swimming, stemless crinoids. The genus first appeared in the fossil record in the Cretaceous period. Characteristics Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate. There is great variability in the morphological features in Antedonids found in different habitats and the main distinguishing feature among the species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ... is the number of cirri. Species The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrus (appendage)
Cirrus may refer to: Science * Cirrus (biology), any of various thin, thread-like structures on the body of an animal * Cirrus (botany), a tendril *Infrared cirrus, in astronomy, filamentary structures seen in infrared light * Cirrus cloud, a type of cloud Aviation * Cirrus aero engines, a series of British aircraft engines manufactured by various companies from the 1920s to the 1950s *Cirrus Aircraft, an aircraft manufacturer in Duluth, Minnesota, USA * Cirrus Airlines, a defunct regional airline in Hallbergmoos, Germany * Cirrus (rocket), a German research rocket first launched in 1961 *Schempp-Hirth Cirrus, an Open-class sailplane * Schempp-Hirth Standard Cirrus, a Standard-class sailplane * Swing Cirrus, a German paraglider design Music * ''Cirrus'' (album), a 1974 release by Bobby Hutcherson * Cirrus (band), an American electronica duo * "Cirrus" (song), a 2013 instrumental by DJ Bonobo * "Cirrus Minor" (song), a 1969 song by Pink Floyd Other uses * Chrysler Cirrus, a car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Parviflora
''Antedon'' is a genus of free-swimming, stemless crinoids. The genus first appeared in the fossil record in the Cretaceous period. Characteristics Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate. There is great variability in the morphological features in Antedonids found in different habitats and the main distinguishing feature among the species is the number of cirri. Species The following species are recognised in the World Register of Marine Species: *''Antedon arabica'' AH Clark & AM Clark *''Antedon bifida'' (Pennant, 1777) *''Antedon duebeni'' Böhlsche, 1866 *''Antedon mediterranea'' (Lamarck, 1816) *''Antedon nuttingi'' (AH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Nuttingi
''Antedon'' is a genus of free-swimming, stemless crinoids. The genus first appeared in the fossil record in the Cretaceous period. Characteristics Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate. There is great variability in the morphological features in Antedonids found in different habitats and the main distinguishing feature among the species is the number of cirri. Species The following species are recognised in the World Register of Marine Species: *''Antedon arabica'' AH Clark & AM Clark *''Antedon bifida'' (Pennant, 1777) *''Antedon duebeni'' Böhlsche, 1866 *''Antedon mediterranea'' (Lamarck, 1816) *''Antedon nuttingi'' (AH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Duebeni
''Antedon'' is a genus of free-swimming, stemless crinoids. The genus first appeared in the fossil record in the Cretaceous period. Characteristics Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate. There is great variability in the morphological features in Antedonids found in different habitats and the main distinguishing feature among the species is the number of cirri. Species The following species are recognised in the World Register of Marine Species: *''Antedon arabica'' AH Clark & AM Clark *''Antedon bifida'' (Pennant, 1777) *''Antedon duebeni'' Böhlsche, 1866 *''Antedon mediterranea'' (Lamarck, 1816) *''Antedon nuttingi'' (AH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Bifida
''Antedon bifida'' is a species of crinoid in the family Antedonidae commonly known as the rosy feather star. It is found in north west Europe. Description The body of ''A. bifida'' is a concave disc surrounded by ten pinnately divided arms giving it a fern-like appearance. The mouth and ambulacral grooves are on the upper surface of the disc. The arms can be up to 10 cm (4 in) long but are usually shorter than this. The undersides of the arms have prominent transverse ridges and some have modifications for feeding and reproduction. The pinnules are jointed, have about 35 segments and bear unequal sized tube feet in groups of three. The arm colour is variable, ranging from yellow or pink to deep purple, sometimes spotted or blotched, and the pinnules are usually paler or white. There are about twenty short cirri, banded and arranged in transverse rows on a central raised ossicle. These curl under and grasp the surface enabling the animal to crawl around which it can do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Arabica
''Antedon'' is a genus of free-swimming, stemless crinoids. The genus first appeared in the fossil record in the Cretaceous period. Characteristics Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate. There is great variability in the morphological features in Antedonids found in different habitats and the main distinguishing feature among the species is the number of cirri. Species The following species are recognised in the World Register of Marine Species: *''Antedon arabica'' AH Clark & AM Clark *''Antedon bifida'' (Pennant, 1777) *''Antedon duebeni'' Böhlsche, 1866 *''Antedon mediterranea'' (Lamarck, 1816) *''Antedon nuttingi'' (AH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Pinnulatus
''Antedon'' is a genus of free-swimming, stemless crinoids. The genus first appeared in the fossil record in the Cretaceous period. Characteristics Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate. There is great variability in the morphological features in Antedonids found in different habitats and the main distinguishing feature among the species is the number of cirri. Species The following species are recognised in the World Register of Marine Species: *''Antedon arabica'' AH Clark & AM Clark *''Antedon bifida'' (Pennant, 1777) *''Antedon duebeni'' Böhlsche, 1866 *''Antedon mediterranea'' (Lamarck, 1816) *''Antedon nuttingi'' (AH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Mediterranea
''Antedon mediterranea'' is a species of stalkless crinoid in the family Antedonidae, commonly known as the Mediterranean feather star. It is found on the seabed at moderate depths in the Mediterranean Sea. It is a filter feeder and captures plankton with its long feathery arms. Description ''Antedon mediterranea'' has a vestigial stalk, the base of which bears up to forty grasping cirri, articulated prehensile structures with which it can cling to a hard surface. Above this is the calyx, a small, cup-shaped structure, which is surrounded by five pairs of arms which bear feathery pinnules. The arms can be rolled up if danger threatens, but when they are extended to feed, they are about long. They are fragile but if one gets broken off, the animal can regenerate it. The colour of this crinoid is quite variable and ranges from white, yellow, orange or red to brown and dark purple, sometimes with bands of contrasting colour. Distribution and habitat ''Antedon mediterranea'' is fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Record
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 absolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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