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Urechinidae
Urechinidae is a family of echinoderms belonging to the order Holasteroida Holasteroida is an order of irregular sea urchins. Characteristics These irregular sea urchins are characterized by a particularly marked bilateral symmetry, including for the apical system, which is highly elongated. In some contemporary ab .... Genera: * '' Antrechinus'' Mooi & David, 1996 * '' Cystechinus'' A.Agassiz, 1879 * '' Pilematechinus'' A.Agassiz, 1904 * '' Urechinus'' A.Agassiz, 1879 References Holasteroida Echinoderm families {{echinoidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urechinidae
Urechinidae is a family of echinoderms belonging to the order Holasteroida Holasteroida is an order of irregular sea urchins. Characteristics These irregular sea urchins are characterized by a particularly marked bilateral symmetry, including for the apical system, which is highly elongated. In some contemporary ab .... Genera: * '' Antrechinus'' Mooi & David, 1996 * '' Cystechinus'' A.Agassiz, 1879 * '' Pilematechinus'' A.Agassiz, 1904 * '' Urechinus'' A.Agassiz, 1879 References Holasteroida Echinoderm families {{echinoidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antrechinus
''Antrechinus'' is a genus of echinoderms belonging to the family Urechinidae Urechinidae is a family of echinoderms belonging to the order Holasteroida Holasteroida is an order of irregular sea urchins. Characteristics These irregular sea urchins are characterized by a particularly marked bilateral symmetry, includ .... The species of this genus are found in the coasts of Antarctica. Species: *'' Antrechinus drygalskii'' *'' Antrechinus mortenseni'' *'' Antrechinus nordenskjoldi'' References Urechinidae Echinoidea genera {{echinoidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holasteroida
Holasteroida is an order of irregular sea urchins. Characteristics These irregular sea urchins are characterized by a particularly marked bilateral symmetry, including for the apical system, which is highly elongated. In some contemporary abyssal groups such as Pourtalesiidae, some species are even bottle-shaped. The mouth (peristome) does not contain an Aristotle's lantern. The anus (periproct) has migrated towards the periphery of the test. The plastron is never amphisternous. Image:MHNT - Hemipneustes pyrenaicus - 1.jpg, Fossile of '' Hemipneustes pyrenaicus'' ( Hemipneustidae, Maastrichtian) Image:Echinosigra amphora.jpg, '' Echinosigra amphora'' ( Pourtalesiidae) This order seems to have appeared at the lower Cretaceous. List of families According to World Register of Marine Species : * Family Hemipneustidae (Lambert, 1917) †** genus '' Hemipneustes'' L. Agassiz, 1835 †** genus '' Medjesia'' Jeffery, 1997 †** genus '' Opisopneustes'' Gauthier, 1889 †... [...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] |
