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''Doulingoceras'' is a genus of ammonoid within the ceratitid order, found in China,that lived during the Late Permian during the time span from about 260.5 to 254 million years ago. The genus is included in the family Paraceltitidae, which belongs to the superfamily Xenodiscaceae. ''Doulingoceras'' produced a narrowly discoidal evolute shell with concave sides, a narrowly rounded rim (venter) that bears several longitudinal lirae, and transverse rigs that have nodes at the umbilical and ventrolateral shoulders that form spiral belts. The suture is identical to that of ''Paraceltites'' in which the lobes are unserrated. ''Doulingoceras'' closely resembles ''Paraceltites'' in the shape of shell and suture; but it may be distinguished from the latter by the concave sides and the node-like transverse ribs in the early stage and two rows of nodes distributed respectively along the ventral edge and the umbilical shoulder at maturity. The type species, ''Doulingoceras nodosum'', named by Zhou, 1985, was originally found in black marine mudstone in the Douling Formation in Hunan Provence, China. ==References== *(GONIAT-online ''Doulingoceras'' entry ) *(The Paleobiology Database ''Doulingoceras'' entry ) 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「Doulingoceras」の詳細全文を読む スポンサード リンク
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