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| authority = Conway Morris & Robinson, 1986 | subdivision_ranks = Families, genera and species (''sensu'' Harvey ''et al.'' 2010〔) | subdivision = See text }} The palaeoscolecids are a group of extinct ecdysozoan worms resembling armoured priapulids. They are known from the Lower Cambrian to the late Silurian;〔 they are mainly found as disarticulated sclerites, but are also preserved in many of the Cambrian lagerstätten. They take their name from the typifying genus ''Palaeoscolex''. == Morphology == Palaeoscolecids bear an annulated trunk ornamented with circular patterns of phosphatic tesselating plates; a layered cuticle; and an armoured proboscis.〔 They are long and narrow, and can reach tens of centimetres in length. Their cuticle is annulated, typically in complete rings, but sometimes the rings split or only encircle part of the trunk. Each annulus is essentially identical to its neighbours; the only trunk differentiation is at the anterior and posterior.〔 The anterior is radially symmetrical, typically comprising an introvert, whereas the trunk is bilaterally symmetrical.〔 The posterior hsots the terminal anus and sometimes one or two hooks.〔 There is no one character that unites the palaeoscolecids as a clade (indeed they are likely paraphyletic), and few individual specimens contain all characteristic palaeosolecid traits.〔 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「palaeoscolecid」の詳細全文を読む スポンサード リンク
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