Brachiopods From The Cambrian “Tsinghsutung Formation”at Balang Village,Jianhe County,Guizhou Province

Sediments of Cambrian Series 2 and Series 3 in Balang, Jianhe area were deposited in the transitional slope belt. The exposed ?Tsinghsutung Formation?(Cambrian Series 2 Stage 4) in this area is 272 m thick. The lower part of this formation is dominated by grey and dark grey limestones; the mid-upper part is composed of light grey thin-bedded limestones intercalated with grey and yellowish-green mudstones; the top part is consisted of dark grey medium-bedded dolomite. Its lithologic chracters are distinct from the typical Tsinghsutung Formation in Western and Northern Guizhou and also different from the coeval Wuxun Formation in Danzhai area, so we temporarily use ?Tsinghsutung Formation? to distinguish. The trilobites within this unit are indicative of Protoryctocephalus arcticus Zone and Arthricocephalus intermedius Zone. Zhang and Robert proposed that the fossil assemblage was buried in situ within deep-water depositional environment.The Jianhe Biota, containing 48 metazoan and 5 algal genera, was discovered in the middle and upper parts of the ?Tsinghsutung Formation? at Balang village, and 6 genera 8 species of brachiopods have been recognized( including 1 conformis and 2 undetermined species), they are: Lingulella sp., Palaeobolus bretonensis, Acrothele sp., Diandongia circularis, Nisusia granosa, Nisusia guizhouensis, Kutorgina cf. cingulata and Kutorgina songshanensis. Four of the six genera belong to the Subphylum Linguliformea. Most of these brachiopods are widespread taxa. Except Diandongia, all the other genera described here also occur in the Kaili Formation.The discovery of brachiopods from the ?Tsinghsutung Formation? not only bridges the Kaili Biota and the Balang Fauna, but also offers insights into the evolution of Cambrian brachiopods.