Bactroptyxis subcochlearis

Bactroptyxis? subcochlearis (Münster in Goldfuss, 1844) Plate 13: figs 16–18 2022 – Bactroptyxis? subcochlearis (Münster in Goldfuss, 1844) – Gründel, Keupp, Lang and Nützel: 199, pl. 13, figs 6–8 (here more chresonymy and synonymy). Material. 6 specimens and fragments, illustrated specimen SNSB-BSPG 2016 XXI 1921. Remarks. The illustrated specimen is 69 mm high. What was suspected in 2022 can now be proven: The early whorls have only 2 strong spiral cords, one directly subsutural, the other well above the abapical suture. Only gradually a weaker spiral cord is formed between the primary spiral cords. The secondary spiral cord remains significantly weaker than the other two throughout ontogeny. Aptyxis kehlheimensis Schlosser, 1882 (pl. 11: figs 3, 5–7; non fig. 4 in Schlosser) has weaker spiral cords and lacks a secondary third spiral cord.