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| image = Choia carteri.jpg | image_caption = ''Choia carteri'' | regnum = Animalia | subregnum = Parazoa | phylum = Porifera | classis = Demospongiae | ordo = Monaxonida | familia= Choiidae | genus = ''Choia'' | type species = ''Choia carteri'' | type species authority = Walcott 1920 | subdivision_ranks = Species | subdivision = * ''C. carteri'' Walcott 1920 * ''C. hindei'' (Dawson, 1896) * ''C. utahensis''Walcott, 1920 * ''C. ridleyi''Walcott, 1920 * ''?C. striata''Xiao et al., 2005 * ''C. xiaolantianensis''Hou et. al. 1999 }} ''Choia'' is a genus of extinct demosponge ranging from the Cambrian until the Lower Ordovician periods. Fossils of ''Choia'' have been found in the Burgess Shale in British Columbia; the Maotianshan shales of China; the Wheeler Shale in Utah; and the Lower Ordovician Fezouata formation. ==Life habit== ''Choia'' was originally thought to be not attached to the sea bed: the living animal was originally thought to rest directly on the substrate, with the radiating spines from the edge of its flattish, conical body, giving an appearance not unlike that of the peak of a big top, with guy lines. Recently discovered fossils from Lower Ordovician Morocco show that the living animal was actually suspended high above the seafloor, attached via stalk-like spines derived from spicules. Water is assumed to have entered the sponge parallel to the spines, being expelled, presumably, from a central opening. Species reached up to an average of 28 mm in diameter. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Choia」の詳細全文を読む スポンサード リンク
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