Abstract: Abundant early vertebrate fossils including galeaspids (Agnatha) and sinacanths (Chondrichthyes) have been known from the Middle Paleozoic deposits of the northwestern margin of the Tarim Basin (Kalpin and Bachu counties), Xinjiang, northwestern China (Wang et al. ,1988; Liu, 1995; Wang et al., 1996; Zhu, 1998; Wang et al., 1998). Here we describe three new forms of galeaspids from the Tataertag Formation (Llandovery, Silurian) near the Tielikewatie village of the Kalpin County, Xinjiang. These new jawless fishes provide us with more evidences on the geographic pro2ximity between the Tarim and Yangtze regions during the Silurian, which is also corroborated by the similarity of the depositional sequence till the Devonian between the two regions. The purplish-red non-marine deposits of the Middle Paleozoic in the Tarim Basin can be subdivided into the Kezirtag, Ymogantau, Tataertag and Kalpintag formations in descending order. Within this sequence, there is no depositional gap or unconformity. Based on the chitinozoans (Geng ,1993) and the continuous sequence, we suggest that the age of the Kezirtag Formation should be the Silurian rather than the early and middle Devonian.

摘要： 描述了新疆柯坪县铁力克瓦铁村附近志留纪兰多维列世塔塔埃尔塔格组无颌类盔甲鱼亚纲的3 个新属、新种。无颌类化石面貌表明,塔塔埃尔塔格组大致与长江中下游的溶溪组相当,其时代为兰多维列世的特列奇期(Telychian) 。塔塔埃尔塔格组时代的更正,使得塔里木盆地和扬子区中古生代地层可直接进行对比。同时,两地鱼群性质和沉积环境的相似性证明,在志留纪时它们可能彼此相距很近。