摘要
对龙爪沟群“Aucellina”的鉴定问题进行讨论,根据新发现的铰合构造,沙金庚等鉴定为Aucellina 的标本应归Buchia 属的晚侏罗世种类。还对海扇类的“假丝梳”(pseudoctenolium) 现象进行探索性研究,沙金庚等认为它是Aucellina 区别于Buchia 的关键,但笔者发现,假丝梳仅是一类种内变异现象,它时而出现、时而消失,在化石和现生标本上均极不稳定,不能作为分类标志,它可能与生境和遗传变异的积累有关;新发现的材料还显示,足丝耳和足丝凹口等也是可变异的特征。因而龙爪沟群“Aucellina”的依据不能成立。
Sha (1990, 1991,1992a,b) and others (Sha and Fürsich, 1994; Gu et al., 1997) proposed a revision for the bivalve fossils from the Longzhaogou and Jixi Groups of NE China, previously the fossils were referred to some Upper Jurassic species of Buchia by Gu et al. (1984) and Chen and Sun (1989). They changed the generic name into Aucellina , and the geological age of the fossil bearing horizons into “middle Barremian-lower Albian” based on a discovery of the structure “pseudoctenolium” on shells.
出处
《古生物学报》
CAS
CSCD
北大核心
1999年第4期454-458,共5页
Acta Palaeontologica Sinica
基金
国家自然科学基金!重点项目(No.49832020)