The First Stalk-eyed Phosphatocopine Crustacean from the Lower Cambrian of China

Exhibiting Orsten-type preservation, specimens of the phosphatocopine Dabashanella sp. from the Lower Cambrian Stage 3 (about 520 million years ago) of southern China possess a single-fold shield and a set of appendages of crustacean design. More significantly, a pair of stalked eyes-the earliest known visual structure in this group-is attached to an ocular segment analogous to the anterior sclerite of various stem-group arthropods. Accordingly, a unique visual system must have been present among some, if not all, early phosphatocopines. In comparison with the ground pattern of later members of this group, the new phosphatocopine, which with its unique head segmentation and limb design is unlikely to be embraced within the previously proposed Labrophora, demonstrates a remarkable modification and innovation in the appendages and visual system with time. Thus, this finding provides new data for the evaluation of the early evolutionary development and phylogenetics of the Crustacea and other related euarthropods.