Members of the Chengjiang Biota from the Lower Cambrian Niutitang Formation, Zunyi County, Guizhou Province, China
YANG Ruidong, ZHANG Weihua, JIANG Lijun, GAO HuiGuizhou University of Technology, Guiyang, 550003
The Chengjiang Biota was called a window of the "Cambrian explosion". The occurrences of the biota are all along restricted in eastern Yunnan Province. Recently, Naronia, Archotuba conoidalis, Isoxys, Persptcaris, Lingulepis, Tsunyidiscus, Scenella, medusiform fossil, Leptomitus, Rhabdopleura fossil, Hyolithids, Zunyiphyton perelegans Yang et Zhao, 1999, Yuknessia sp. , Longenema Ding, 1996, Sphaerocangregus variabilis were discovered in the Lower Cambrian Niutitang Formation of Zunyi County, Guizhou Province, China. Among them, Naronia, Archotuba conoidalis, Isoxys, Yuknessia sp. , medusiform fossil and Leptomitus are members of the Chengjiang Biota. The Biota from the upper part of the Niutitang Formation is called the " Zunyi Biota". It is the first time for Chengjiang-type Biota to be found outside Yunnan Province. Additionally, the "Songlin Biota" from the base of the Niutitang Formation, containing abundant sponge fossils, Arthropoda and algal fossils, has been found at 40 m beneath the occurring horizon of the "Zunyi Biota". Over the "Zunyi Biota", Early Cambrian Archaeocyathan fauna occur in the Mingxinsi Formation. Therefore, the discovery of the biota is of great importance to the study of evolution of Early Cambrian biota in Guizhou Province. Simultaneously, it is also important for the palaeoecological study of the Chengjiang Biota.