Figure 6

Micromitra burgessensis and Pirania muricata from the middle (Series 3, Stage 5) Cambrian Burgess Shale. A, ROM63169, RQ + 8.2 m, plan view of M. burgessensis. B, ROM63186, BW-210 cm, Plan view of P. muricata. C, ROM63188, BW-210 cm, Plan view of P. muricata. D-E, ROM63189, BW-170 cm. D, Plan view of P. muricata and M. burgessensis, scale bar 2 mm. E, close up of M. burgessensis and the sponge wall of P. muricata, scale bar 1 mm. F-G, ROM61135, BW-200 cm. F, Close up of rhomboidal texture of the sponge wall of P. muricata, scale bar 1 mm. G, Close up of shell ornament on M. burgessensis, scale bar 1 mm. H, ROM63187, WQ-170 cm, Close up of P. muricata spicules (arrow is used to indicate sponge spicules on the left of the image) juxtaposed with M. burgessensis chaetae (right of the image), scale bar 1 mm. I, GSC 81224, Walcott Quarry, Phyllopod Bed, Plan view of M. burgessensis with P. muricata spicules emerging from underneath the shell. Scale bars 5 mm unless otherwise stated.