Carboniferous euomphaloids with preserved protoconch (one openly coiled (A), one tightly coiled (B)) reflecting non-planktotrophic early ontogeny. (A) Euomphalus sp. SNSB-BSPG 2023 I 87, Locality 28 (Marohn) of Yoo (1994): Scone 1:25,000, GR 084544. Bioclastic limestone in the upper part of the Dangarfield Formation, 150 m west of ‘Marohn’ homestead, 4 km south-west of Gundy, Early Carboniferous, Tournaisian. (A1) Apertural view. (A2) Umbilical view. (A3, A4) Detail of openly coiled initial whorl; arrows mark end of protoconch. (B) Amphiscapha catilloides (Conrad, 1842), SNSB-BSPG 2023 I 88, Graham Formation, Finis Shale Member, Pennsylvanian, Texas, USA. (B1) Umbilical view. (B2) Protoconch of less than one whorl, demarcated by a ledge (arrow).