广西隆林祥播早二叠世茅口期的几种Pseudodoliolina

广西隆林祥播地区二叠纪地层是一套连续的海相碳酸盐岩,出露良好,内含丰富的(竹蜓)类化石。本文记述了Pseudodoliolina属的12种,其中对2个新种Pseudodoliolina contracta sp.nov.,P.subelliptica sp.nov.作详细描述。新种均采于茅口阶Cancellina带。新种的发现为本文论述Pseudodoliolina(竹蜓)类动物群的演化特征提供了实际材料。

SOME SPECIES OF Pseudodoliolina FROM THE MAOKOU STAGE OF EARLY PERMIAN AT XIANBO, LONGLIN, GUANGXI

Specimens of the fusulinids dealt with in this paper were collected in the autumn of 1985 from the Maokou Stage of Middle Permian at the Xiangbo Section which is located on the southwest flank of the Anran Anticline about 30 km west of the town of Longlin, Guangxi. The Permian sequences are continuous and extensively exposed. The upper and middle parts of the Maokou Stage are composed of reef carbonates or light gray massive framestones in organic reef facies, whereas the lower part is composed of bioclastic grainstone, sparite and wachestone. The biomicrite consists of foraminifera, calcareous algae, fusulinids, bryozoans, rugose corals, echinodermatas and belongs to biological shoal facies. The fusulinaceans dealt with in this paper comprise twelve species of Pseudodoliolina genus,of which two are new. The new species occur in the Cancellina zone in the lower part of the Maokou Stage, where fusulinaceans are very abundant in the Canceooina zone and Pseudodoliolina consists mostly of individuals . This paper has a brief discussion on the evolution of the genus according to the stratigraphic sequences.