Moult stages and dimorphism of Early Cambrian bradoriids from Xichuan, Henan, China

摘要: Carapaces or valves of 6 species bradoriids are described from the Early Cambrian (Canglangpu Stage) Shuigoukou Formation in Xichuan, Henan, China. They comprise four genera, including two new genera: Ovaluta gen. nov. is established for some found China which were previously under name Aluta; Phaseolella nov., with distinctive carapace features, should be referred to phosphatocopines. The five proposed Monasterium bucerum, Houlongdongella xichuanensis, henanensis, dimorpha, and P. curvata. Abundant bradoriids, isolated by etching limestone dilute acid, permitted detailed study their ontogeny. sexual dimorphism may earliest (Lower Cambrian) record so far known Bradoriida, demonstrated growth curve a scatter diagram. Growth this isometric juvenile stages but anisometric pre-adult-adult stages. Nevertheless, separate moult could not distingui...