Fig. 68. Problematicum Coleoloides Walcott, 1889 in Early-middle Cambrian stratigraphy and faunas from northern Siberia

Fig. 68. Problematicum Coleoloides Walcott, 1889, internal moulds of tubes, from the lower Cambrian Erkeket (C, D), Tyuser (M), and Pestrotsvet (A, B, E–L) formations, Siberia, Russia; samples 11/2B (C) and 11/16.1 (D) from Khorbusuonka River; sample 21/22 (M) from lower reaches of Lena River; sample M303/2 (B, H, J, L) from Tiktirikteekh Brook (Rozanov et al. 1969: 31, text-fig. 6), sample 171–174 (E) from Bydyangaya Brook (Val'kov 1982: 27, textfig. 8) middle reaches of the Lena River, sample 479a (K) from section "Dvortsy", Aldan River, and sample 510 (A, F, G, I) from section Ulakhan-Sulugur, Aldan River (Fig. 1). A–C, K–M. Coleoloides trigeminatus Missarzhevsky in Rozanov et al., 1969, SMNH X11324–11329, respectively. D. Coleoloides sp., SMNH X11330. E–J. Coleoloides cf. paucistriatus Poulsen, 1967, SMNH X11331–11336, respectively. A1, B2, C2, E1, F2, G1, H2, I1, L2, lateral view; A2, B1, C1, F1, H1, L1, transversal view; E2, G2, I2, transversal view in the apical part. Scale bar: 500 µm (M) and 250 µm (A–L).