寒武纪三叶虫Sinoproceratopyge kiangshanensis Lu的卷曲与蜕壳

摘要

An enrolled meraspid trilobite specimen of Sinoproceratopyge kiangshanensis Lu,collected from the upmost part of Furongian of Cambrian in Jiangshan,Zhejiang Province,is described.It is well preserved except the thoracic segments covered by the cephalon.With the free cheek splitting from the fixed cheek,it is believed that in the process of exuviation,the enrolling was an inevitable movement.With a big cephalon,small pygidium and a few thoracic segments,the Sinoproceratopyge kiangshanensis is considered to be completing on enrollment,probably then a "hemispiral enrollment".The enrollment is similar to that of the trilobites from Upper Cambrian of Missouri in America,but different from that of Stephanocare from Liaoning.%标本为Sinoproceratopyge kiangshanensis Lu的未成年体(分节期),采自浙江江山碓边寒武系芙蓉统排碧阶最上部Sinoproceratopyge kiangshanensis 带.标本明显卷曲,除大部分胸节被压于头甲之下,其余保存较好.自由颊与固定颊明显裂开,并略有错位,推测为一正在蜕壳的标本,卷曲属蜕壳过程中的行为.因头大尾小,胸节数不多,认为其有完全卷曲的能力,可能属半螺旋型卷曲.与美国密苏里寒武系芙蓉统三叶虫和中国辽宁复洲湾Stephanocare的卷曲进行了比较讨论,认为与美国密苏里寒武系芙蓉统三叶虫的卷曲相似而与辽宁复洲湾Stephanocare的卷曲不同.