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Echinarachniidae
Echinarachniidae is a family of echinoderms belonging to the order Clypeasteroida Sand dollars (also known as a sea cookie or snapper biscuit in New Zealand, or pansy shell in South Africa) are species of flat, burrowing sea urchins belonging to the order Clypeasteroida. Some species within the order, not quite as flat, are k .... Genera Genera: * '' Astrodapsis'' Conrad, 1856 * '' Echinarachnius'' Gray, 1825 * '' Faassia'' Shmidt, 1971 References Clypeasteroida Echinoderm families {{echinoidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clypeasteroida
Sand dollars (also known as a sea cookie or snapper biscuit in New Zealand, or pansy shell in South Africa) are species of flat, burrowing sea urchins belonging to the order Clypeasteroida. Some species within the order, not quite as flat, are known as '' sea biscuits''. Sand dollars can also be called "sand cakes" or "cake urchins". Anatomy Sand dollars are small in size, averaging from three to four inches. As with all members of the order Clypeasteroida, they possess a rigid skeleton called a test. The test consists of calcium carbonate plates arranged in a fivefold symmetric pattern. The test of certain species of sand dollar have slits called lunules that can help the animal stay embedded in the sand to stop it from being swept away by an ocean wave. In living individuals, the test is covered by a skin of velvet-textured spines which are covered with very small hairs (cilia). Coordinated movements of the spines enable sand dollars to move across the seabed. The velvety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinarachnius
''Echinarachnius'' is a genus of sand dollars, belonging to the family Echinarachniidae . Kroh, A.; Mooi, R. (2020). World Echinoidea Database. Echinarachnius Gray, 1825. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=158061 on 2020-12-31 Species of ''Echinarachnius'' have been around since the Pliocene epoch. Species *†'' Echinarachnius alaskensis'' Durham, 1957 *'' Echinarachnius asiaticus'' Michelin, 1859 *†'' Echinarachnius humilis'' Nisiyama, 1968 *†'' Echinarachnius kewi'' Grant & Eaton in Eaton, Grant & Allen, 1941 *†'' Echinarachnius naganoensis'' Morishita, 1953 *''Echinarachnius parma ''Echinarachnius parma'', the common sand dollar, is a species of sand dollar native to the Northern Hemisphere. Kroh, A.; Mooi, R. (2020). World Echinoidea Database. Echinarachnius parma (Lamarck, 1816). Accessed through: World Register of Mari ...'' (Lamarck, 1816) *†'' Echinarachnius rumoensis'' Hayasaka & Sh ... [...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] |
