内蒙古大青山地区奥陶纪鹦鹉螺化石新材料

NEW LOWER ORDOVICIAN NAUTILOIDER FOSSILS IN DAQINGSHAN MOUNTAIN REGION,INNER MONGOLIA

共描述鹦鹉螺化石 3个种 (其中一个新种 )、5个未定种和一个属种未定 ,分属 4个科。这些化石产自内蒙古大青山地区一套白云质灰岩中 ,对于该套地层的研究已有很长的历史 ,但由于没有发现确切的生物化石 ,其时代一直很难确定 ,多数专家将其划归晚元古代什那干群。通过细致的野外工作 ,在该套地层中发现了大量早奥陶世的生物化石 ,除文中描述的鹦鹉螺外 ,与之伴生的还有笔石、腹足类和腕足类等化石 。

The paper has discribed 3 species and 5 species indeterminata,including 1 new species The fossils are found in a series strata of carbonate which had been classified into Shinagan group of upper Protozoic by former geologist The research of the strata in the region have long history,but have not gotten prominent progress in biofossils researching,so the age of the strata have uncertain for a long time,the discovery of fossils,Nautiloidea,Graptolithina,Gastropoala and Brachiopoda can provide a certain evidence,it can be concluded that the strata must be lower Ordovician