Fig. 24 in Early-middle Cambrian stratigraphy and faunas from northern Siberia

Fig. 24. Molluscs from the lower Cambrian Erkeket Formation, Khorbusuonka River (A–F, J–N) and Sekten Formation, lower reaches of the Lena River (G–I), Siberia, Russia; samples 11/2B (E, F, J), 11/16.1 (K, M, N), 19/12.75 (A), 19/11.75 (B), 20/1B (L, O, P), 20/6B (C, D), and 22/50 (G–I). A, B. Davidonia anabarica (Parkhaev, 2005), internal moulds, SMNH Mo194701 and 194702, respectively. C. Mellopegma sp., internal mould, SMNH Mo194713. D. Stenotheca cf. drepanoida (He and Pei in He et al., 1984), silicified shell, SMNH Mo194714. D1, lateral view; D2, oblique apertural view. →