Fig. 2
From: Tube-dwelling in early animals exemplified by Cambrian scalidophoran worms
Selkirkia sinica from the early Cambrian Chengjiang Lagerstätte: gut tract and gut contents. a ELI-00001405, showing fully everted introvert and basal part of trunk protruding beyond the tube opening. b ELI-00002012, showing sinuous gut inside introvert. c ELI-00002013, showing thin and straight gut tract and, posteriorly, two ovoid elements interpreted as possible unusually large pellets or undigested shells. d ELI-00002014, showing fully everted introvert and 3D-preserved aligned pellet-like elements in gut. e, f ELI-00002015, showing more randomly distributed pellet-like elements in the gut (compared with d), elemental maps (see location in e). Abbreviations: gc, gut contents; sg, straight gut; sig, sinuous gut; tr, trunk; ue, undigested element (possibly shell). Scale bars represent a, d and e 5 mm; b, c 2 mm; f 200 μm