Fig. 66 in An early Cambrian fauna of skeletal fossils from the Emyaksin Formation, northern Siberia

Fig. 66. Echinoderm thecal-plates of unknown affinity from lower Cambrian Emyaksin Formation, Bol'shaya Kuonamka River, Anabar Uplift, Siberia; sample 7/70, except A, sample K1-3B. A. SMNH Ec 31528, outer view of elliptical plate with straight truncated-margin bearing 4 notches; external (A1) and oblique lateral (A2) views. B. SMNH Ec 31529, triangular, thick plate with one curved (abutment?) surface; B1, outer?, convex surface; B2, inner?, concave surface; B3, view of curved abutment? surface (to the top in B1 and B2). C–F. Rounded to trapezoidal-plate with truncated margin bearing comb-like structure (sutural-gaps?). C. SMNH Ec 31530, trapezoidal plate with comb-like structure (to the top) and opposite, tuberculated, facet (to the base); lateral (C1) and outer? (C2) views. D. SMNH Ec 31531, plate with reduced comb-like structure on truncated margin; D1, view of truncated margin; D2, convex, outer? surface (truncated-margin to the top); D3, concave, inner? surface (truncated-margin to the top). E. View of ellipsoidal truncated margin bearing shallow comb-like structure; SMNH Ec 31532. F. SMNH Ec 31530, rounded plate; F1, oblique, inner? view; F2, comb-like structure. G. SMNH Ec 31534, smooth, concavo-convex thecal-plate bearing small rounded epispires (to the back-right); oblique lateral-view. Scale bar 600 μm.