Amphicutis stygobita development, all dorsal (aboral) except 6F A baby #3 with skin and possible primary plates, 19 September 2018 B baby #3, skin on disk and arm, 31 December 2018 C baby #2, disk pentagonal, arms with grooved terminal plate and terminal tube foot, 30 October 2018 D baby #2 full of detritus, probable DAP, 29 December 2018 E baby #2, 13.5 months old, some arms have 3rd arm segments with 1-2 terminal spines, 14 September 2019 F baby #2 ventral (oral) surface showing parts of stereom, 9 April 2019: 1 madreporite, 2 disk scales, 3 adoral shield spine, 4 ventral tooth, 5 dental plate, 6 oral tentacle, 7 VAP #1, 8 VAP #2, 9 LAP, 10 ambulacral plate, 11 3rd segment outside disk, 12 terminal plate. Abbreviations: DAP – dorsal arm plate, PP – primary plates, TP – terminal plate, TTF – terminal tube foot.