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Antedon
''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 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 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 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] |
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 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] |
Antedonidae
Antedonidae is a family of crinoids or feather stars in the phylum Echinodermata. Members of the family are unstalked and have ten feathery arms. They can move about freely and have clawed cirri to attach them temporarily to structures. Marine Species Identification Portal. Retrieved 2011-10-11. Genera The following genera are recognised by the World Register of Marine Species: * sub-familia Antedoninae (Norman, 1865) ** genus '' Andrometra'' AH Clark, 1917 -- 2 species ** genus ''[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antedon Petasus
''Antedon petasus'' is a marine invertebrate, a species of crinoid or feather star in the family Antedonidae. It is found around the coasts of north west Europe. Description ''A. petasus'' has a conical disc with five pairs of arms, each up to long and fringed with pinnules, giving it a feathery appearance. The pinnules are smooth on the underside and are varyingly coloured in blotches of white, red and brown. On the underside of the disc are 50-100 short curled cirri with which the animal moves around and clings to the substrate.''Antedon petasus'' Marine Species Identification Portal. Retrieved 2011-10-16.''Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crinoidea
Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. They live in both shallow water and in depths as great as . Adult crinoids are characterised by having the mouth located on the upper surface. This is surrounded by feeding arms, and is linked to a U-shaped gut, with the anus being located on the oral disc near the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, in most crinoids the five arms are subdivided into ten or more. These have feathery pinnules and are spread wide to gather planktonic particles from the water. At some stage in their lives, most crinoids have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Articulata (Crinoidea)
Articulata are a subclass or superorder within the class Crinoidea, including the only living crinoid species. They are commonly known as sea lilies (stalked crinoids) or feather stars (unstalked crinoids). The Articulata are differentiated from the extinct subclasses by their lack of an anal plate in the adult stage and the presence of an entoneural system. Articulata first appeared in the fossil record during the Triassic period although other, now extinct crinoid groups, originated in the Ordovician. Characteristics Articulata exhibit pentamerous symmetry. The stalk, which consists of numerous disks held together by ligaments, supports a calyx or cup made of circlets of calcerous plates. In Comatulids, the stalk develops following the larval stage, but the juveniles shed all but the topmost disk to take up a free-living existence. Five often branched arms, which consist of articulated series of ossicles, extend from the oral plate and form the food-capture mechanism of Articula ... [...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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