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''Microdictyon'' is an extinct "armored worm" coated with net-like scleritic scales, known from the Early Cambrian Maotianshan shale of Yunnan China. ''Microdictyon'' is sometimes included in a somewhat ill-defined Phylum – Lobopodia – that includes several other odd worm-like and segmented free-swimming animals that do not appear to be arthropods or worms. The phylum includes ''Microdictyon'', ''Onychodictyon'', ''Cardiodictyon'', ''Luolishania'', ''Paucipodia'', as well as the Anomalocaridids. The isolated sclerites of ''Microdictyon'' are known from other Lower Cambrian deposits. ''Microdictyon'' sclerites appear to have moulted; one sclerite seems to have been preserved during ecdysis.〔Figured in 〕 ''Microdictyon sinicum'' (Chen, Hou and Lu, 1989) is typical. The wormlike animal has ten pairs of sclerites (suggestions that these may be eyes or eye-like structures have no weight) on the sides, matched to a pair of tentacle-like feet below. The head and posterior are tubular and featureless. == Species composition == *Type species. ''Microdictyon effusum'' Bengtson, Matthews et Missarzhevsky, 1981; Lower Cambrian, Atdabanian Stage, Kazakhstan; Atdabanian and Botomian Stages, Russia (Siberian Platform) and England; Lower Cambrian, Sweden. In addition to the type species, eleven species: *''M. anus'' Tong, 1989, Lower Cambrian, upper Meishucunian Stage (= Atdabanian Stage), China (Shaanxi). *''M. chinense'' Hao et Shu, 1987, Lower Cambrian, Qiongzhusi Stage (= upper Atdabanian-lowermost Botomian Stages), China (Shaanxi); Atdabanian through Botomian stages, Siberian Platform. *''M. depressum'' Bengtson, 1990, Lower Cambrian, Atdabanian through Botomian Stages, South Australia. *''M. fuchengense'' Li et Zhu, 2001, Lower Cambrian, upper Meishucunian Stage (Atdabanian Stage), China (Shaanxi). *''M. jinshaense'' Zhang et Aldridge, 2007, Lower Cambrian, Qiongzhusi Stage (= upper Atdabanian Stage-lowermost Botomian), China(Shaanxi).〔 *''M. rhomboidale'' Bengtson, Matthews et Missarzhevsky, 1986, Lower Cambrian, upper parts of the Atdabanian Stage, Kazakhstan; Atdabanian Stage, Canada, the United States (''M. cf. rhomboidale''). *''M. robisoni'' Bengtson, Matthews et Missarzhevsky, 1986, Middle Cambrian, Amgan Stage, the United States; *''M. rozanovi'' Demidenko, 2006, Lower Cambrian, Toyonian Stage, Siberian Platform.〔 *''M. sinicum'' Chen, Hou et Lu, 1989, Lower Cambrian, upper Meishucunian Stage (= Atdabanian Stage) Stage, China (Yunnan. *''M. sphaeroides'' Hinz, 1987, Lower Cambrian, Atdabanian Stage, Great Britain. *''M. tenuiporatum'' Bengtson, Matthews et Missarzhevsky, 1986, Lower Cambrian, Atdabanian Stage, Siberian Platform. A picture can be found at http://paws.wcu.edu/dperlmutr/earlyfauna.html. ---- The name ''Microdictyon'' is also used for a genus of green algae. 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「Microdictyon」の詳細全文を読む スポンサード リンク
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