Fig. 1

All figures are of columnal latera unless otherwise indicated. Scale bar 100 μm. a En echelon perforate stereom with elliptical lumina. Balanocrinus quiaiosensis de Loriol. Jurassic, Sinemurian, Charmouth Mudstone Formation, Quedgeley, Gloucestershire, England. BM. b En echelon perforate stereom with elliptical lumina. Balanocrinus subteroides (Quenstedt). Jurassic, Pliensbachian, Charmouth Mudstone Formation, Blockley, Gloucestershire, England. BM E70552. c En echelon perforate stereom with weakly elliptical lumina. ‘Isocrinus’ angulatus (Oppel). Jurassic, Hettangian, Waterloo Mudstone Formation, Larne, Co. Antrim, Northern Ireland. BELUM K2010.4. d En echelon perforate stereom with elliptical lumina, slightly etched. Isocrinus psilonoti (Quenstedt). Jurassic, Hettangian, Blue Lias Formation, Tewkesbury, Gloucestershire, England. BM. e En echelon perforate stereom with elliptical lumina. Isocrinus robustus (Wright). Jurassic, Pliensbachian, Charmouth Mudstone Formation, Scunthorpe, Humberside, England. BM. f En echelon perforate stereom with near circular lumina. Hispidocrinus scalaris (Goldfuss). Jurassic, Sinemurian, Charmouth Mudstone Formation, Bishops Cleeve, Gloucestershire, England. BM. g En echelon perforate stereom with elliptical lumina. Hispidocrinus schlumbergeri (de Loriol). Jurassic, Sinemurian, Charmouth Mudstone Formation, Charmouth, Dorset, England. BM h Sinuous perforate stereom with circular to elliptical lumina. Pentacrinites fossilis Blumenbach. Jurassic, Sinemurian, Charmouth Mudstone Formation, Charmouth, Dorset, England. BM