|
''Proterovaginoceras'' (Ancient Greek for "earlier shield horn") is a medium to large sized endocerid (endocone-bearing orthoconic nautiliod) from the Early and Middle Ordovician included in the family Endoceratidae. ''Proterovaginoceras'' has a straight shell with a circular cross section, straight sutures, and a ventral to central, nanno-type, siphuncle which fills the entire apical part of the shell. Septal necks are macrochoanitic, up to two camerae (chambers) long; connecting rings, one chamber in length line the inside of the necks. Endocones are long and slender, fill the entire bulbous, nanno-end, of the siphuncle. ''Proterocameroceras'' was named by Reudemann in 1905. ''Dideroceras'' Flower 1950 and ''Chisloceras'' Gortani 1934 are probably synonymous equivalents. ==References== * Tiechert,C. 1964. Endoceratoidea. Treatise on Invertebrate Paleontology, Part K. Endoceratoidea, Actinoceratoidea, Nautiloidea. Geological Soc. of America and Univ Kansas Press. *(''Proterovaginoceras'' ) in (Paleobiology Database ) 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「Proterovaginoceras」の詳細全文を読む スポンサード リンク
|