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Carnarechinidae
''Carnarechinus clypeatus'' is a species of sea urchins of the Holasteroida order. This species was described on the basis of fragmentary and poorly preserved material from Philippines, hence its taxonomic status is still unclear. Molecular phylogeny indicates it may be a basal member of the Urechinina. References Carnarechinusat the Natural History Museum A natural history museum or museum of natural history is a scientific institution with natural history collections that include current and historical records of animals, plants, fungi, ecosystems, geology, paleontology, climatology, and more. ... * Holasteroida Monotypic echinoderm genera 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] |