Family Chionelasmatidae Buckeridge, 1983 (Upper Cretaceous–Recent)
Archaeochionelasmus KOČÍ, BUCKERIDGE & NEWMAN gen. nov. Pl. 1, figs A–F; Pl. 2, figs A–H; Text-figs 3, 6
Diagnosis. Low conical neobalanoform with a six-plated wall comprised of a carina (C) and a rostrum (R) plus paired carinolatera (CL1) and rostrolatera (RL) and at least one whorl of basal imbricating plates (IPs); pseudo-radii present on overlapping margins of RL and CL1; alae unexposed, rostrolatera perhaps included in the sheath; no trace of a calcareous basis.
Etymology. Archaeo (Greek arkhaio-) = early, or before Chionelasmus .
Stratum typicum. Upper Cenomanian, Korycany Member, Bohemian Cretaceous Basin.