内蒙古达茂旗巴特敖包地区包尔汉图剖面牙形刺生物地层

内蒙古达茂旗(达尔罕茂明安联合旗)巴特敖包地区志留纪、泥盆纪碳酸岩相地层发育，本区珊瑚、腕足类、层孔虫等底栖大化石的研究工作已有一定基础。但志留纪、泥盆纪地层在时代确定和对比上还存在很多问题，必须用主导化石门类牙形刺加以解决。研究表明：包尔汉图剖面的顶部属泥盆系无疑，应归入阿鲁共组，而不是西别河组；巴特敖包地区的海侵，始于罗德洛统卢德福德阶(Ludfordian)早期。本剖面没有发现文洛克世和罗德洛世早期的海相沉积。本文描写了一个志留纪牙形刺新种：Ozarkodina uncrispa sp．nov．。

CONODONT BIOSTRATIGRAPHY OF THE BAOERHANTU SECTION IN DARHAN MUMINGAN JOINT BANNER, INNER MONGOLIA

Silurian and Devonian carbonate strata are widely distributed in the Bateaobao area, Darhan Mumingan Joint Banner, Inner Mongolia. Previouse studies are mainly fucused on corals, brachiopods, stromatoporoides and other benthic faunas. Many problems about the ages of Silurian and Devonian rocks and their correlations still remain to be solved. by the leading fossil groups such as conodonts. The conodont study clearly shows that the upper part of the Baorhantu section should be early Early Devonian, assignable to the Alugong Formation rather than the Xibiehe Formation. We have not found the records of the Wenlock and early Ludlow marine deposits and fossils in Bateaobao area. Silurian transgression in this area started during early Ludfordian. One conodont new species, Ozarkodina uncrispa sp. nov., is described in this paper.