Fig. 18 in An early Cambrian fauna of skeletal fossils from the Emyaksin Formation, northern Siberia

Fig. 18. Pelagiellid mollusc Pelagiella sp. 1, external mould of the outer shell surface, from lower Cambrian Emyaksin Formation, Bol'shaya Kuonamka River, Anabar Uplift, Siberia; sample 7/70. A. SMNH Mo 167683, sinusoidal course of transverse ribs of the shell exterior. B. SMNH Mo 167684; B1, transversal ribs fade out distally; B2, close-up of B1. Scale bar: A, B1, 300 μm; B2, 120 μm.