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Nemaster
''Nemaster'' is a monotypic genus of echinoderms belonging to the family Comatulida Comatulida is an order of crinoids. Members of this order are known as feather stars and mostly do not have a stalk as adults. The oral surface with the mouth is facing upwards and is surrounded by five, often divided rays with feathery pinnules .... The only species is ''Nemaster grandis''. The species is found in Central America and Australia. References Comatulidae Crinoid genera Monotypic echinoderm genera {{crinoidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comatulidae
Comatulidae is a family of comatulid crinoids. Since 2015, it replaces the family Comasteridae. Description and characteristics This family is of recent restoration, and still has no consensual description. However the description of the family Comasteridae remains partially valid. This family counts between 93 and 95 species, distributed in 21 genera, which makes it the second most diversified family of crinoids the behind Antedonidae, representing approximately 1/6th of known crinoid species. It contains most of the big species of shallow tropical feather stars, in particular in the Indo-Pacific. List of genera This family has been recently restored following genetic works from Charles Messing's team. It contains the following genera: * sub-family Comatellinae Summers, Messing, Rouse, 2014 ** genus '' Alloeocomatella'' Messing, 1995 -- 2 species ** genus '' Comatella'' AH Clark, 1908 -- 2 species ** genus '' Davidaster'' Hoggett & Rowe, 1986 -- 2 species ** genus '' N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Genus
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, '' Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda.' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoderm
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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comatulida
Comatulida is an order of crinoids. Members of this order are known as feather stars and mostly do not have a stalk as adults. The oral surface with the mouth is facing upwards and is surrounded by five, often divided rays with feathery pinnules. Comatulids live on the seabed and on reefs in tropical and temperate waters. Taxonomy Bourgueticrinida, the sea lilies, has traditionally been viewed as an order of Articulata and a sister taxon to Comatulida. A study published in 2011 suggested that it should be renamed Bourgueticrinina and viewed as a suborder of Comatulida. Characteristics Like other echinoderms, comatulids have pentamerous symmetry (five sided) as adults though the larvae have bilateral symmetry. Late in their development, the larvae are attached to the seabed by a stalk, but this is broken at metamorphosis and the juvenile crinoid is free living. The body has an endoskeleton made from a number of articulated calcareous plates known as ossicles covered by a thin e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crinoid Genera
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 a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
