贵州黔东世(早寒武世)杷榔组Changaspis Lee in Chien,1961的再研究

RESTUDY OF CHANGASPIS(LEE),1961 FROM QIANDONGIAN(EARLY CAMBRIAN)BALANG FORMATION NEAR EASTERN GUIZHOU,SOUTH CHINA

掘头虫类三叶虫张氏虫ChangaspisLee in Chien,1961是黔东、湘西广泛分布的杷榔组中常见的化石。本属化石建立7个种,具有较高的多样性。近年在贵州东部地区的杷榔组采集到此属化石的大量标本,特别是在剑河交榜村的杷榔组发现了Changaspis丰富的化石,提供了分类学再研究的重要材料。据新的化石标本的详细鉴定、个体发育观测及数理统计数据的对比、化石埋藏状态的研究,Changaspis已描述的7个种是过高估计,原属C.micropygeChien,1961,C.elongataLee in Chien,1961,C.placentaQian et Lin in Zhanget al.,1980,C.longispina(Lee,in Egorovaet al.,1963),C.nangaoensisLu et Chien in Yin and Lee,1978,C.?transversaZhou in Zhouet al.,1977和C.taihuensisZhang et Zhou,1985之间形态差异并不明显。C.micropyge,C.placenta应为C.elongata的晚出同义名,而C.longispina,C.nangaoensis,C.taihuensis和C.transversa建种时化石标本少,保存不好,应是C.elongata晚出同义名。

Changaspis of oryctocephalid trilobite is common at the Balang Formation in east Guizhou and west Hunan.Up to date seven species have been described,including C.micropyge Chien,1961,C.elongata Lee in Chien 1961,C.placenta Qian et Lin in Zhang et al.,1980,C.longispina（Lee,in Egorova et al.,1963）,C.nangaoensis Lu et Chien in Yin and Lee,1978,C.？ transversa Zhou in Zhou et al.,1977 and C.taihuensis Zhang et Zhou,1985.Recently,a large number of specimens of Changaspis are found in the Balang Formation in Jiaobang village,Jianhe county,eastern Guizhou.New findings provide important information for taxonomy of Changaspis.Based on detailed examination of ca.100 specimens of Changaspis elongata and using statistics and mathe-matical analysis on the characters of ontogenetic change,we suggest that 7 species of Changaspis are over-split in the taxonomic species-level classification.These species（C.micropyge,C.placenta,C.longispina,C.nangaoensis and C.？ transversa,both C.micropyge,C.placenta）should be considered to be synonyms of Changa-spis elongata.Other species assigned to the genus base on uncompleted specimens are not considred valid and should be assigned to Changaspis elongata.