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Seguenzioidea is a superfamily of minute to medium-sized sea snails, marine gastropod mollusks in the clade Vetigastropoda. 〔 Gofas, S. (2010). Seguenzioidea. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) World Marine Mollusca database. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=224565 on 2011-01-09 〕 ==Description== The distinctive characteristics of the shells of the Seguenzioidea are: * the nacreous layer (a plesiomorphic character, i.e. a character state that a taxon is inferred to have been retained from its ancestors) This occurs also in the following families: Pleurotomariidae, Haliotidae, Turbinidae, Trochidae, and possibly in the Skeneidae. * the protoconch has a trochoid shape. * usually with one or more labral sinuses. This character is also found is several other superfamilies such as Neomphaloidea, Pleurotomarioidea, Fissurelloidea, and Scissurellidea and in the families Siliquariidae and Turridae. Therefore, this characteristic is to be considered autapomorphic. * a unique radular formula with an underlying rhipidoglossate ground plan. 〔 (James F. Quinn Jr., (1991), Systematic Position of Basilissopsis and Guttula, and a Discussion of the Phylogeny of the Seguenzioidea (Gastropoda: Prosobranchia), Bulletin of Marine Science, Volume 49, Numbers 1-2, September 1991 , pp. 575-598(24) ) 〕 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「Seguenzioidea」の詳細全文を読む スポンサード リンク
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