The genus Yangtzedonta Yu,1985 have not been accepted by bivalve specialists as a bivalve as Yu originally reported in studying early phylogeny and evolution of the class Bivalvia. Recently, Qian Yi(2001) solved this puzzle. He confirms that Y.primitiva Yu is only an incomplete specimen of Xianfengella prima He et Yang, a problematical small shelly fossil. It is a pity that Qian confused Xianfengoconcha elliptica Zhang with the oldest certain bivalve. It is necessary to review comprehensively the study of Cambrian bivalves in China. Xiangfengoconcha Zhang,1980 shows an elongate, weakly inclined anterior and posterior toothlike structure on each side of the beak. This is an obolellid-type hinge structure rather than the bivalve palaeoheterodont type. Moreover lamellar teeth of palaeoheterodonts were derived from the fusion of discrete teeth of palaeotaxodont type. Therefore, it is unlikely that the most primitive bivalve was such a form with lamellar teeth as Xianfengoconcha elliptica Zhang. At present, Pojetaia Jell, 1980 is the only undoubted Cambrian bivalve in China.
