An orthonauplius of 'Orsten'-type preservation from the Upper Cambrian (Furongian) of South China

Abstract

A tiny larva of ʻOrstenʼ-type of three-dimensional preservation has been recovered from the Upper Cambrian Bitiao Formation of Wangcun section, western Hunan, South China, herein in- terpreted as an orthonauplius stage of a crown-group crustacean. The specimen comprises an ovoid body with a prominent labrum and three pairs of appendages. In all it exhibits comparable morpho- logical similarities with the type-A larvae described earlier from other ʻOrstenʼ-type deposits. The new orthonauplius can be considered to represent a new form of type-A larvae. Such larvae represent a morpho-type and were previously reported from the Cambrian palaeo-microcontinents Laurentia, Baltica, and Australia; their find now also from South China implies a pandemic distribution. With this, type-A larvae have the widest and longest-lasting record of all Cambrian crustaceans, possibly even euarthropod fossils described so far.