中文摘要：

贵州剑河八郎寒武系黔东统清虚洞组由泥岩和灰岩组成,厚约300m,沉积相属于黔东陆棚深水过渡相区沉积类型,不同于黔西以浅水台地相白云岩和灰岩为主的典型清虚洞组类型。该组三叶虫化石丰富,包括莱德利基虫目Redlichia（Redlichia）guizhouensis,R.（R.）nobilis;褶颊虫目对沟虫科Eoptychoparia jinshaensis,Antagmus dapingensis,褶颊虫科Nangaops brevis;耸棒头虫目叉尾虫科Olenoides hupeiensis,Kootenia sp.,以及掘头虫类中的掘冠虫科Ovatoryctocara sp.,掘头虫科Changaspis elongata,C.cf.elongata和飞龙山虫科Duyunaspis cf.duyunensis;共计9属7种2相似种及2未定种。本文描述了其中具重要地层意义的掘头虫类三叶虫3属4种,包括2未定种。结果表明,在黔东清虚洞组发现的掘头虫类Changaspiselongata和Duyunaspis cf.duyunensis,此前仅报道于该组之下的杷榔组,现这两种的层位可上延至清虚洞组上部;同时显示该组Ovatoryctocara sp.和凯里组下部的Ovatoryctocara granulata比较相似,有可能是Ovatoryctocara granulata的祖先种。掘头虫类三叶虫的新资料将有助于促进国际寒武系第3统底界层型剖面及点位（GSSP）的进一步研究。

英文摘要：

The Tsinghsutung Formation near Balang village, Jianhe County, Guizhou Province, belonging to the eastern Guizhou lithozone, is more than 300 m in thickness and mainly composed of dark grey thin bedded limestones and mudstones, which is different from the light grey thick bedded dolostones and limestones in the western Guizhou lithozone. The upper part of the formation is rich in trilobites, including 9 genera, 7 species, 2 conformis species and 2 indefinite species, i.e. Redlichia （Redlichia） guizhouensis, R. （R.） nobilis, Eoptychoparia jinshaensis, Antagmus dapingensis, Nangaops brevis, Olenoides hupeiensis, Kootenia sp.,Ovatoryctocara sp., Changaspis elongata, cf. elongata and Duyunaspis cf. duyunensis, of which Redlichia and Antagmidae C. are most common and typical of the Redlichia （R.） guizhouensis-Redlichia （R.） nobilis Acme Zone in the upper part of the Tsinghsutung Formation. The oryctocephalid trilobites Changaspis elongate and Duyunaspis cf. duyunensis formerly reported from the underlying Balang Formation are described for the first time in this paper from the upper part of the Tsinghsutung Formation.Moreover, Ovatoryctocara sp.,a form closely similar to Ovatoryctocara granulata from the overlying beds （lower part of the Kaili Formation） may likely be an ancestral species of O. granulata. The new discovery of the oryctocephalid trilobites is therefore significant for the further work on the global boundary stratotype section and point （GSSP） for the base of Cambrian Series 3.