A new euarthropod with large frontal appendages from the early Cambrian Chengjiang biota

We describe Fengzhengia mamingae gen. et sp. nov., a new euarthropod from the lower Cambrian (Series 2, Stage 3) Chengjiang Lagerstatte, Southwest China. Fengzhengia mamingae possesses prominent frontal appendages, stalked, circular eyes, a simple, sub-triangular head shield, and a trunk with 15 tergites, the anterior nine each bearing a single medial axial spine. Limited evidence suggests biramous trunk appendages with paddle-shaped exopods. At the posterior end is a sub-triangu-lar region, possibly a pygidium, articulated with a tail fan. The frontal appendage of F. mamingae resembles those of certain 'great appendage' arthropods and Isoxys. We test the affinities of F. mamingae by parsimony and Bayesian analyses and tentatively suggest that it is an early branch of Deuteropoda. We suggest that F. mamingae may have been a nektobenthic scavenger or predator, and its dorsal exoskeleton is notable for exhibiting defensive spines.