Fig. 13 in An early Cambrian fauna of skeletal fossils from the Emyaksin Formation, northern Siberia

Fig. 13. Helcionellid mollusc Pararaconus sp. internal mould from lower Cambrian Emyaksin Formation, Bol'shaya Kuonamka River, Anabar Uplift, Siberia; SMNH Mo 160421, sample 7/70. A. Lateral view. B. Sub-apical view. C. Close-up of D. D. Polygonal texture on the apical surface of internal mould. E. Upper view. F. Pits on the surface of mould near the aperture. Scale bar: A, B, E, 600 μm; D, 120 μm; C, F, 30 μm.