Fig. 47 in Early-middle Cambrian stratigraphy and faunas from northern Siberia

Fig. 47. Hyolith opercula "Orthothecid operculum type A", from the lower Cambrian Tyuser Formation, lower reaches of the Lena River, Siberia, Russia; sample 21/21. A–H. Phosphatised opercula, SMNH X11182–11189, respectively. B1, outer surface; B2, oblique dorsal; D1, inner surface; and D2, oblique lateral views. Scale bar 500 µm.