Ceratoconus Chen and Zhang, 1980

Kouchinsky, Artem, Bengtson, Stefan, Landing, Ed, Steiner, Michael, Vendrasco, Michael & Ziegler, Karen, 2017, Terreneuvian stratigraphy and faunas from the Anabar Uplift, Siberia, Acta Palaeontologica Polonica 62 (2), pp. 311-440 : 355

Genus Ceratoconus Chen and Zhang, 1980

→ Fig. 23. Mollusc Aldanella cf. sibirica Parkhaev and Karlova, 2011 , internal moulds, from early Cambrian Emyaksin Formation, Bol’shaya Kuonamka River, eastern Anabar Uplift, Siberia, Russia; samples 5a/34.75 (A–H), 5a/17.5 (I, J), and 5a/34.5 (K), section 96-5a. A–K. SMNH Mo182273–182283, respectively. A 1, D, E 1 –G 1, H 2, I, J 1, K 1, adapical side; A 2, B 2, C, E 2 –G 2, J 2, K 2, apertural views; H 1, apical area with polygons enlarged. Scale bar 200 μm (H 1), 500 μm (A–G, H 2).

Type species: Ceratoconus striatus Chen and Zhang, 1980 ; middle Meishucunian Stage ( upper Fortunian ), lower Cambrian; Yunnan Province, South China .

Remarks.— Ceratoconus is different from Salanyella Missarzhevsky, 1981 (see below), in having a more elongated shell. Yu (1987) synonymized Ceratoconus with Pollicina Holzapfel, 1895 . Thus, Pollicina striata ( Chen and Zhang, 1980) occurs in fossil lists from the upper Fortunian– Cambrian Stage 2 equivalents of western Mongolia (basal Unit 20 of the Bayan Gol Formation, Tiksitheca licis Zone ; Voronin et al. 1982; Esakova and Zhegallo 1996; Brasier et al. 1996) and lower Medvezhya Formation of the western Anabar Uplift (Kaufman et al. 1996).