文中图示和描述了重庆城口大塘口奥陶系红花园组和湄潭组下部营盘段的几丁虫计 6属, 17种。其中包括 7个未定种和 3个新种 (Conochitinadatangkouensissp. nov., C. wengxigouensissp. nov., Rhabdochitinachenk ouensesp. nov. )。讨论了几丁虫的地理和地层分布特点及其与笔石生物带的关系,阐明了红花园组和湄潭组下部营盘段不同笔石带(A. filiformis, D. bifidus和A. suecicus笔石带)中几丁虫的组合特征,并与国外同期地层几丁虫组合进行了对比。

Summary The Ordovician sequence is complete and well exposed at Datangkou of Chengkou County, Chongqing City. The investigation has been carried out on chitinozoans, together with the graptolites and conodonts, from the Honghuayuan Formation and the Yingpan Member of the Meitan Formation which represents the late Early Ordovician and early Middle Ordovician in the eastern Dabashan, belonging to the north Yangtze carbonate platform. For this study thirty-five chitinozoan samples were collected so that a stratigraphical control can be expected based on graptolite or conodont zones in this interval. Chitinozoans are lacking in eleven samples while in others are abundant but poorly diversified. A total of seventeen species, three new species (Conochitina datangkouensis sp. nov., C.wengxigouensis sp. nov., Rhabdochitina chenkouense sp. nov.) included, belonging to six genera have been described and figured. Among the key species recorded, the FAD of Lagenochitina esthonica, C. poumoti, C. brevis and ?Eremochitina brevis allow biostratigraphical correlation with graptolite zones of the same section and chitinozoan zones from Quebec, Bohemia, and south-eastern Europe. Yet, we must emphasize the absence of the typical Conochitina symmetrica which is unrecorded in the Honghuayuan Formation.

Q915.813

国家自然科学基金(No. 40272020)资助课题