Abstract:
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.
