在龙爪沟群七虎林组中识别出多个时代分布仅限于早白垩世晚期至晚白垩世早期的双壳类化石属，其中，Vectianella Casey和Pseudaphrodina Casey的时代分布仅限于早白垩世阿普第期，这两个属的发现对于七虎林组和龙爪沟群时代的确定有重要意义。文中系统描述这两属化石，并简要探讨七虎林组的时代。

Several bivalve genera or species, ranging from the late Early Cretaceous to early Late Cretaceous, have been found in the Qihulin Formation of the Longzhaogou Group. Among them, the age of Vectianella Casey and Pseudaphrodina Casey is confined to Aptian as known so far, which has great significance to date the Qihulin Formation and Longzhaogou Group. In this paper, the two genera as well as their type species are described systematically, and the age of the Qihulin Formation is also briefly discussed and dated as mainly Aptian.

Q915

中国科学院知识创新工程项目 (KZCX2 114 )，国家自然科学基金 (No .40 0 72 0 0 4)资助课题