Hyolithids in the gut of <i>Ottoia prolifica</i>

<p><b>from the middle Cambrian Burgess Shale.</b> A, ROM 61753a, showing 3 hyolithids preserved with their opercule. B–E, ROM 61782, with 5 hyolithid shells (<i>Haplophrentis carinatus</i>) within the gut, their apex pointing anteriorly; general view and details. F–H, USNM 196381, with 6 hyolithid shells within the gut. I, USNM 188604, with 3 hyolithids (h3 close to the anus). Abbreviations: ANT, anterior; an, trunk annulation; co1–co3, hyolithid conch 1 to 3; gc, gut content; gu, gut; he, helen; h1–h6, from anterior, hyolithid 1 to 6; op1–op3, hyolithid operculum 1 to 3; lo, loop; ph, posterior hook; POST, posterior; tr, trunk. Scale bar: 1 cm for B, F, H, I; 5 mm for A, C–E; 2 mm for G.