河南西峡盆地晚白垩世含恐龙蛋地层中的双壳类

描述河南西峡盆地含恐龙蛋地层的双壳类5属(亚属)9种,其中1新种。依据双壳类的地层分布特征,确认含恐龙蛋地层的时代属晚白垩世,很可能为晚白垩世中-晚期(Coniacian-Campanian期)。描述的双壳类化石有:Pseudohyria cf.gobiensis MacNeil,Pseudohyria cf.cardiiformis(Martinson),cf.Plicatounio(Plicatounio)hunanensis Zhang,cf.Plicatounio(Plicatounio)zhuchengensis Ma,Plicatounio(Acclinoplicatounio)cf.nan-anensis Ma et Huang,Plicatounio(Tamuraia)henanensis Chenet Wangsp.nov.,Sphaerium shantun gense(Grabau),Sphaeriumtani Grabau和Sphaerium laiyangense Chen。其中,Pseudohyria属及Tamuraia和Accli-noplicatounio亚属的历程均限于晚白垩世。韩国和日本早白垩世地层发现的Pseudohyria matsumotoi Yang,1979应归Matsumotoina,不属于Pseudohyria;福建禾口组上部原鉴定为Plicatounio(Plicatounio)naktongensis和Pli-catounio(Plicatounio)fujianensis的标本,应改归Tamuraia亚属。

LATE CRETACEOUS NON-MARINE BIVALVES FROM THE DINOSAUR EGG-BEARING STRATA OF XIXIA BASIN,HENAN,CHINA

This paper firstly describes the bivalves from the non-marine Cretaceous in Xixia Basin of the southwestern part of Henan Province,China.The Late Cretaceous strata in Xixia Basin,made up mainly of red beds,are divided into three formations,namely(in ascending order) the Gaogou,Majiacun and Sigou Formation.Dinosaur eggs found from the Gaogou Formation are classified as Longiteresoolithus xixiaensis,Prismatoolithus gebiensis,Yungoolithus xiagouensis,Paraspheroolithus cf.irenensis,P.yangchengensis and Dendroolithus zhaoyingensis;from the Majiacun Formation are Longiteresoolithus xixiaensis,Paraspheroolithus sp.,Paraspheroolithus cf.irenensis,Dendroolithus sanlimiaoensis,D.dendriticus,Ovaloolithus sp.and Sphaeroolithus sp.;and from the Sigou Formation is Paraspheroolithus sp.(Zhou et al.,1983;Wang and Zhou,1996;Wang et al.,2006).Based on the study of the morphological characters of the eggs and the microstructure of the eggshells,some vertebrate scientists(e.g.,Zhao and Li,1988;Zhao,2003) were of the opinion that the dinosaur egg-bearing strata belong to the age of Early Cretaceous.The bivalves described in this paper were collected from the Gaogou and Majiacun formations.They are assigned to the following 9 species of 5 genera(subgenera):Pseudohyria cf.gobiensis MacNeil,1936,Pseudohyria cf.cardiiformis(Martinson,1953),cf.Plicatounio(Plicatounio) hunanensis Zhang,1979,cf.Plicatounio(?Plicatounio) zhuchengensis Ma,1983,Plicatounio(Acclinoplicatounio) cf.nananensis Ma et Huang,in Huang and Ma,1979,Plicatounio(Tamuraia) henanensis Chen et Wang sp.nov.,Sphaerium shantungense(Grabau,1923),Sphaerium tani Grabau,1923,and Sphaerium laiyangense Chen,1984.