|
Oligopygoida
Oligopygoida is an extinct order of irregular Echinoidea, echinoids. The group is closely related to the Clypeasteroida, and may be representative of its ancestral clypeasteroid. The order was once grouped together with the cassiduloids. However unlike them, oligopygoids have a well-developed lantern uncommon amongst urchins and holectypoids, but similar to that of clypeasteroids. Phylogenetic analysis has shown the clypeasteroids to be a sister group to oligopygoids.Mooi, Rich (1990). ''Paedomorphosis, Aristotle's Lantern, and the Origin of the Sand Dollars (Echinodermata: Clypeasteroida)''. Paleobiology. 16 (1). Pages 26-46. However they are differentiated by the lack of accessory ambulacral pores, which are characteristic of that group. They also have well-developed petals above small, wedge-shaped demiplates. Each of these have simple ambulacral pore. The presence of these demiplates is unique to this order. The apical disk is monobasal, with a deep sunken typically sun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoma (sea Urchin)
''Microsoma'' is a genus of flies in the family Tachinidae. Species *''Microsoma exiguum'' ( Meigen, 1824) *''Microsoma vicinum ''Microsoma vicinum'' is a species of fly in the family Tachinidae. Distribution Japan, Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest co ...'' (Mesnil, 1970) References Dexiinae Brachycera genera Taxa named by Pierre-Justin-Marie Macquart Diptera of North America Diptera of Asia Diptera of Europe {{dexiinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoidea
Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of sea urchins are round and spiny, ranging in diameter from . Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines. Although algae are the primary diet, sea urchins also eat slow-moving (sessile) animals. Predators that eat sea urchins include a wide variety of fish, starfish, crabs, marine mammals. Sea urchins are also used as food especially in Japan. Adult sea urchins have fivefold symmetry, but their pluteus larvae feature bilateral (mirror) symmetry, indicating that the sea urchin belongs to the Bilateria group of animal phyla, which also comprises the chordates and the arthropods, the annelids and the molluscs, and are found in every ocean and in every climate, from the tropics to the polar ... [...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] |
