湖北利川晚二叠世长兴期生物礁中的鹦鹉螺化石及其生态意义

川东、鄂西碳酸盐台地东缘,较广泛地发育着以海绵动物为骨架的生物礁。礁中有许多附礁生物,其中鹦鹉螺类化石在利川见天坝礁体中局部富集,共有8属9种,包括3个新种。根据现代鹦鹉螺的生态特征及当时区域沉积物的分布规律分析,工作区长兴期沉积环境是处在台地边缘,并接近斜坡相和盆地相。

STUDY OF NAUTILOIDS IN THE UPPER PERMIAN CHANGXINGIAN REEFS FROM LICHUAN,WEST HUBEI

The Lichuan district is located in the east margin of the carbonate platform of the Permian in the east Sichuan and the West Hubei. Along the marginal area, reefs are widely distributed. The reef mentioned in this paper has been studied in detail since the 1960s. Besides main frame-building organisms, such as sphinctozoan calcisponges, and binding organisms (blue-green algae and Tubiphytes),there are also many organisms attached to the reef, such as Foraminifera, Bryozoans, Cephalopods, Bivalvia, Brachiopods , Gastropods and Nautiloids. This paper gives a detailed study of Nautiloids. The following genera are identified : Liroceras, Pleuronautilus, Domatoceras, Lopingoceras, Permonau-tilus, Foordiceras ,Mooreoceras and Aulagoniceras,including 9 species with 3 new species. In this reef, Nautiloids well preserved are of a variety of size, found in random positions. It is shown that they are untransported oryctocoenose. Among these Nautiloids, Permonautilus and Liroceras are the most abundant, their shapes are very similar to that of the Nautilus, which is the only surviving genus today.