Fig. 4

The non-biomineralized artiopodan Sinoburius lunaris from the early Cambrian (Stage 3) Chengjiang. a YRCP 0011, dorsal view of specimen photographed under light microscopy. b Dorsal view of specimen photographed under fluorescence microscopy. c Ventral view of three-dimensional computer model based on X-ray tomographic data rendered in Drishti [73]. d Close up of head region in ventral view. e Close-up of uniramous antennae with antennal scale. Arrowheads indicate podomere boundaries in antennae. Abbreviations: ans, antennal scale; ant, antennae; en, endopod; ex, exopod; ey, eye; gs, genal spine; gn, gnathobases; hs, head shield; hyp, hypostome; ls, lateral spine; ms, median spine; pg, pygidium; Tn, thoracic segment