• 责任者：Wang Zhihao (Nanjing Institute of Geology and Palaeontology ; Chinese Academy of Sciences ; Nanjing 210008 ; China) ; Stig Bergströ ; m
• 刊名：Acta Palaeontologica Sinica
• 出版年：2013
• 卷期：30(4)
• 关键词：牙形石 ; conodonts ; 奥陶纪 ; Ordovician ; 内蒙古 ; Inner Mongolia
• 页码：p.323-343
• 图表：5 illus., 3 plates, 1 table, 53 refs.
• 分类号：1100
• issnNo：ISSN0001-6616
• isbnNo：CN32-1188/Q

     This paper describes the Ordovician conodont fauna from the Dashimen section near Wuhai City in Inner Mongolia, China. The Histiodella fauna, that includes mainly Histiodella kristinae, H. holodentata, Polonodus newfoundlandensis, Paroistodus horridus and a new species Histiodella wuhaiensis, was found in the Lower Klimoli Formation, which is referred to the Histiodella kristinae Zone of the Middle Ordovician Darriwilian Stage. The study interval Contains graptolites corresponding to the Pterograptus elegans and lower part of the Didymograptus murchisoni zones. The discovery of Histiodella fauna in this section is important not only for biostratigraphic correla tion but also for the facies and palaeogeographical interpretations. Because the top part of the Lower Klimoli Forma tion yields Histiodella kristinae, Baltoplacognathus cf. reclinatus, Periodon aculeatus and Protopanderodus rectus, etc. , it may correspond to the basal part of the Pygodus serra Zone. At the base of the Wulalik Formation, a con glomeratic limestone lens contains Yangtzeplacognathus protoramosus , Protopanderodus liripipus , P ygodus anseri nus？ and Dapsilodus viruensis, which may be tentatively referred to the Pygodus anserinus Zone. However, the specimens questionably referred to the zone index P. anserinus are not typical and there is a possibility that this level may rather represent the Yangtzeplacognathus protoramosus Subzone of the P. serra Zone, which is the highest sub zone of the P. serra Zone in China. The key graptolite Nemagraptus gracilis appears less than 10 m above the con glomeratic limestone lens. This section is particularly important because the conodont-bearing limestones are interca lated with graptolite shales which permits a close correlation between conodont and graptolite zones. The new species Histiodella wuhaiensis is described and the morphological differences between five Histiodella species are discussed in detail.