|
Cephalodiscida
Cephalodiscida is one of two orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordata, hemichordates. Species in this order are Sessility (zoology), sessile, living in clear water and secretion, secrete tubes on the ocean floor. Taxonomy The order is a small one, with only two known families, each containing a single extant genus. The validity of the family Atubaridae, who has only a sole member, is regarded as questionable. * Order Cephalodiscida Fowler 1892 ** Family Cephalodiscidae Harmer 1905 *** Genus †''Aellograptus'' Obut 1964 *** Genus †''Eocephalodiscus'' Kozlowski 1938 ex Kozlowski 1949 *** Genus †''Melanostrophus'' Öpik 1930 ex Öpik 1933 *** Genus †''Pterobranchites'' Kozlowski 1967 *** Genus ''Atubaria'' Sato 1936 *** Genus ''Cephalodiscus'' M'Intosh 1882 ** Family †Rotaciurcidae Briggs and Koch 2023 *** Genus †''Rotaciurca'' Briggs and Koch 2023 References Harmer. S. F. 1905. The Pterobranchia ol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterobranchia
Pterobranchia, members of which are often called pterobranchs, is a class of small worm-shaped animals. They belong to the Hemichordata, and live in secreted tubes on the ocean floor. Pterobranchia feed by filtering plankton out of the water with the help of cilia attached to tentacles. There are about 25 known living pterobranch species in three genera, which are '' Rhabdopleura'', '' Cephalodiscus'', and '' Atubaria''. On the other hand, there are several hundred extinct genera, some of which date from the Cambrian Period. The class Pterobranchia was established by Ray Lankester in 1877. It contained, at that time, the single genus '' Rhabdopleura''. ''Rhabdopleura'' was at first regarded as an aberrant polyzoon, but when the ''Challenger'' report on '' Cephalodiscus'' was published in 1887, it became clear that ''Cephalodiscus'', the second genus now included in the order, had affinities with the Enteropneusta. Electron microscope studies have suggested that pterobranch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalodiscidae
''Cephalodiscus'' is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida. Description All known species live in a secreted coenecium attached to a rock substrate. Unlike ''Rhabdopleura'', ''Cephalodiscus'' species do not form large colonies and are only pseudocolonial, but they do share a common area with individual buds for each zooid. ''Cephalodiscus'' zooids are also more mobile than their ''Rhabdopleura'' counterparts, and are able to move around within tubaria. ''Cephalodiscus'' zooids can be produced via asexual budding. There are a few pairs of tentacled arms, whereas ''Rhabdopleura'' has only one pair of arms. Species 19 living species of ''Cephalodiscus'' have been described: * '' Cephalodiscus agglutinans'' Harmer & Ridewood, 1914 * '' Cephalodiscus atlanticus'' Bayer, 1962 * '' Cephalodiscus australiensis'' Johnston & Muirhead, 1951 * '' Cephalodiscus calciformis'' Emig, 1977 * '' Cephalodiscus densus'' Andersson 1907 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalodiscus
''Cephalodiscus'' is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida. Description All known species live in a secreted coenecium attached to a rock substrate. Unlike ''Rhabdopleura'', ''Cephalodiscus'' species do not form large colonies and are only pseudocolonial, but they do share a common area with individual buds for each zooid. ''Cephalodiscus'' zooids are also more mobile than their ''Rhabdopleura'' counterparts, and are able to move around within tubaria. ''Cephalodiscus'' zooids can be produced via asexual budding. There are a few pairs of tentacled arms, whereas ''Rhabdopleura'' has only one pair of arms. Species 19 living species of ''Cephalodiscus'' have been described: * '' Cephalodiscus agglutinans'' Harmer & Ridewood, 1914 * '' Cephalodiscus atlanticus'' Bayer, 1962 * '' Cephalodiscus australiensis'' Johnston & Muirhead, 1951 * '' Cephalodiscus calciformis'' Emig, 1977 * '' Cephalodiscus densus'' Andersson 1907 ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemichordata
Hemichordata ( ) is a phylum which consists of triploblastic, eucoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and include two main classes: Enteropneusta (acorn worms), and Pterobranchia. A third class, Planctosphaeroidea, is known only from the larva of a single species, '' Planctosphaera pelagica''. The class Graptolithina, formerly considered extinct, is now placed within the pterobranchs, represented by a single living genus '' Rhabdopleura''. Acorn worms are solitary worm-shaped organisms. They generally live in burrows (the earliest secreted tubes) and are deposit feeders, but some species are pharyngeal filter feeders, while the family are free living detritivores. Many are well known for their production and accumulation of various halogenated phenols and pyrroles. Pterobranchs are filter-feeders, mostly colonial, living in a collagenous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotaciurca
''Rotaciurca'' is an extinct genus of Silurian cephalodiscid pterobranchs. The genus contains a single species, ''Rotaciurca superbus'', known from the Bertie Group of Ontario, Canada. Description ''Rotaciurca'' is a pseudocolonial (containing multiple clustered individuals which are not connected) pterobranch, unique for being a cephalodiscid rather than a graptolite. The cluster consists of a ring of radiating tubes, likely containing the living individuals, attached to a conical structure interpreted as a float, giving the original fossil the nickname of "Ezekiel's wheel". The whole organism is roughly long, seemingly with two distinct rows of tubes. Its pterobranch affinity is confirmed by lineations within the tubes, which are traces of fuselli, and the irregular arrangement of these group it with the cephalodiscids. ''Rotaciurca'' has a number of similarities to '' Yuknessia'', another enigmatic fossil recently described as a pterobranch, including rigid and similarly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atubaridae
''Atubaria heterolopha'' is a species of hemichordates in the monotypic genus ''Atubaria'' and in the monotypic family Atubaridae. This taxon belongs to the pterobranchian order Cephalodiscida. It was described by Tadao Sato in 1936 from specimens found feeding on a colony of the hydrozoan '' Dycoryne conferta'' in Sagami Bay, Japan. Description The characteristics of this pterobranch species include a 1–5 mm long zooid, a collar with four pairs of tentaculated arms, a single pair of pharyngeal slits, and a solitary and sedentary behaviour. It closely resembles ''Cephalodiscus ''Cephalodiscus'' is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida. Description All known species live in a secreted coenecium attached to a rock substrate. Unlike ''Rhabdopleura'', ''Cephalodiscu ...'' members. References {{taxonbar, from=Q3827927 Pterobranchia Animals described in 1936 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Biology, biological Kingdom (biology), kingdom Animalia (). With few exceptions, animals heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, have myocytes and are motility, able to move, can reproduce sexually, and grow from a hollow sphere of Cell (biology), cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million extant taxon, living animal species have been species description, described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from to . They have complex ecologies and biological interaction, interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
