Fig. 6
From: Tube-dwelling in early animals exemplified by Cambrian scalidophoran worms
Selkirkia transita sp. nov. from the early Cambrian Chengjiang Lagerstätte: general morphology. a–e ELI-0000601, holotype, Selkirkia transita sp. nov., general view, line drawing, and details of introvert structure and ornament. f–h ELI-0000602, paratype, showing introvert, possible oblique retractor muscles and annulations along tube. i ELI-0000603, paratype, showing part of introvert. Abbreviations: an, annulation; in, introvert; rm?, possible retractor muscles; tb, trunk boundary; tr, trunk; tu, tube. I, II and III represent divisions Zone I, Zone II and Zone III of the introvert, respectively. Ia, Ib, Ic represent the subdivisions of Zone I. Green lines and grey areas in b represent the gut and inner surface of the tube, respectively. White dotted lines in c, e show scalids and pharyngeal teeth arranged in quincunx, respectively. Scale bars represent a, f, and i 5 mm; c–e, g and h 1 mm