SEMs of Amphilepis platytata A enlarged view of mouth area in Fig. 14D, oral tentacle pores without scales B oracle tentacle inside tentacle pore, no scales C partially bleached string of 8 arm segments, broad DAPs and LAPs, dorsal, distal right D bleached string of vertebrae, spine articulations on LAPs, dorsal, distal right E string of 4 vertebrae with muscles connecting flanges, ventral, distal right F distal face of proximal vertebra showing muscle flanges, median process, and articulating surfaces. Abbreviations as in Fig. 12 plus: DMF – dorsal muscle flange, M – muscle, MP – median process, OT – oral tentacle, OTP – oral tentacle pore, PB – podian basin, VMF – ventral muscle flange.