A–F Caecum pulchellum A, C, E, F specimen ZSM-Mol-20090485 B, D juvenile specimen ZSM-Mol-20200118 A, B light microscopic pictures C, D SEM scans E close-up of mucro and F microsculpture H–K C. donmoorei, specimen USNM 1618844 H–K C. regulare, specimen ZSM-Mol-20100321, juvenile H light microscopic picture I SEM scans J close-up of mucro and K microsculpture L–T C. cf. teres and C. cf. strangulatum L specimen ZSM-Mol-20200033, juvenile specimen with larval shell still attached M, N, Q, S specimen ZSM-Mol-20200032, juvenile M light microscopic picture N SEM scan Q close-up of mucro and S microsculpture O, P, R, T C. cf. strangulatum, specimen ZSM-Mol-20200038, juvenile O light microscopic picture P SEM scan R close-up of mucro and T microsculpture U–X C. cf. semilaeve, specimen ZSM-Mol-20200034 U Light microscopic picture V SEM scan W close-up of mucro and X microsculpture. Scale bars: 10 µm (F, S, T, W, X); 20 µm (J, K, Q, R); 50 µm (E); 100 µm (H, I, L–P, U, V); 200 µm (A–D).