Fig. 1
From: Tube-dwelling in early animals exemplified by Cambrian scalidophoran worms
Selkirkia sinica from the early Cambrian Chengjiang Lagerstätte: general body plan, trunk and possible paired caudal appendages. a–c ELI-0002001, Selkirkia sinica, general view, line drawing and close-up of introvert. d ELI-0002002, showing shrinked remains of the trunk and a tapering trunk end. e, f ELI-0002003, showing strongly shrinked trunk and bifurcating trunk ends and close up of corresponding structures. g–i ELI-0002004, showing possible bifurcating structures at the posterior end of the trunk, general view, close-up and X-ray Fluorescence (XRF) image (note that bifurcating structures and trunk both have comparable elemental distribution). Abbreviations: an, anus; bte, possible bifurcated trunk ends; sg, straight gut; tr, trunk. Scale bars represent a, d, e and h 5 mm; c, f and g 1 mm