Hypermecaspis (三叶虫 )的蜕壳  

TECHNIQUES OF EXUVIATION IN HYPERMECASPIS (TRILOBITA)

作　　者：韩乃仁[1] 王嘉玲[1] 

机构地区：[1]桂林工学院,广西桂林541004

出　　处：《古生物学报》2000年第3期419-424,共6页Acta Palaeontologica Sinica

摘　　要：在中国 ,只在浙江江山早奥陶世印渚埠组顶部的Arenig期发现有HypermecaspisasiataHan一个种。文中的Hypermecaspis采自江山横塘及竹余 ,和江山城北 4km公路两侧的印渚埠组顶部。仅有少数标本保存有头盖 ,大部分只保留有自由颊、胸与尾 ,极少相对移位 ,应为原地埋葬标本 ,所发现的Hypermecaspis几乎全为蜕壳标本。面线起机能作用 ,面线裂开 ,头盖与胸部分离 ,头盖还表现为翻转 ,胸部有时会裂开 ,部分胸节翻转 ,表明在蜕壳时胸部会耸起 ,而后再平复。面线裂开 ,新生虫体顶着头盖爬向前。Hypermecaspis的蜕壳方式应该是Arenig期小尾类三叶虫蜕壳的主要形式。McNamara和Rudkin (1984)以及Heningsmoen (1975 )所叙述的三叶虫蜕壳类型中 ,并没有类似的情况。In China, only one species of Hypermecaspis , i. e. H. asiata Han was found from the top of Yinzhufu Formation of the top Lower Ordovician in Jiangshan, Zhejiang Province. The psesent specimens were collected from the top of Yinzhufu Formation at three localities in Jiangshan area, viz. Hentang, Zhuyu and a place 4 km north to Jiangshan. In these specimens, mostly the librigena, thorax and pygidium are preserved, only a few with cranidia, and few displaced relatively, therefore these specimens belong to autochthonous remains. Almost all the Hypermecaspis are moulting specimens. Serving as the function of moulting, the facial suture split, the cranidium was separated from the thorax, and was turnd; sometimes the thorax split and part of thoracic segments were turned, which reflects during moulting the thorax bulged, and then flattened; when the facial suture split, the new animal crawled forward carrying the old cranidium. The exuvial model of Hypermecaspis could be a major one in micropygious type trilobites. The exuvial model of trilobites interpreted by McNamara and Rudkin (1984) and Heningsmoen (1975), is not similar to this case.

关 键 词：Hypermecaspis 蜕壳 早奥陶世 三叶虫 

分 类 号：Q915[天文地球—古生物学与地层学]