闽西船山组上部的介形类

OSTRACODA FROM UPPER CHUANSHAN FORMATION IN WEST FUJIAN

一、前言福建晚古生代介形类迄今尚无专门报道。近年来,笔者从沙县高地ZK302钻孔岩芯及龙岩中甲剖面的部分样品中,获得了较为丰富的介形类化石,共计12属18种,其中2新种,2未定种。所产介形类化石的岩性为灰色、深灰色生物碎屑微晶灰岩;层位局限于船山组上部,即广义的Pseudoschwagerina带。与介形类共生的(竹蜓)类有Sphaeroschwagerina, Pseudoschwagerina, Eoparafusulina等;珊瑚Anfractophyllum, Pseudocarniaphyllum, Kepingophyllum等。样品的采集工作得到洪祖寅、吴富宝的帮助,扫描电镜照片承袁留平完成。

The fossil ostracods described in this paper were collected from the upper Chuanshan Formation, Gaodi of Shaxian, which is corresponding to the 'Pseudoschwagerina Zone (s.1.)' of the fusulinid assemblage zone in west Fujian. This ostracode fauna contains 18 species in 12 genera, including 2 new species, and may be called the Bairdia menardensis-Basslerella shaxianensis Assemblage.Based on the characteristics, this assemblage possibly belongs to Early Permian in age, corresponding to Wolfcampian, but it still remains a problem to be further discussed.DESCRIPTION OF NEW SPECIES Basslerella shaxianensis sp. nov. (P1. Ⅱ, figs. 7, 8)Carapace small, subroundly triangular in lateral view. Dorsal margin strongly arched outward; anterodorsal margin short, while posterodorsal margin straight and long, with a length of more than 1/2 the length of carapace. Venter broadly flat, with a ventral plane. Ventral margin flat and straight. Carapace suboval in lateral view. Left valve a little larger, slightly overlapping the right; hinge line straight. Carapace surface smooth.Comparison The new species is relatively similar to Basslerella erassa Kellett, but in the former, the posterodorsal angle is indistinct, the posterodorsal margin is long and straight, the venter has a ventral plane, and the carapace has a thickness greater than its height.Cavellina sphenoformis sp. nov. (P1. Ⅱ, figs. 11, 12)Carapace small, nearly cuneate in lateral view. Anterior end nearly truncate, while posterior end broadly round. Posteroventral part of carapace with a sinus, while mid-dorsal part with ancther broad and shallow sinus. Carapace cuneate in dorsal view, with the thickest part in the postetior, symmetrical bilaterally. Right valve larger, slightly overlapping the left. Carapace surface smooth.