Parietal plication of Plectopylidae species (diagrammatic figures). A Hunyadiscus saurini sp. n. B–E main character states of Endothyrella, Gudeodiscus, Halongella, Sicradiscus and Sinicola (mainly after Páll-Gergely and Hunyadi 2013 and Páll-Gergely et al. 2015b and Páll-Gergely and Asami 2016) F Hunyadiscus andersoni (W. Blanford 1869). Blue colour indicates the anterior lamella and its homologous structures; red colour indicates the posterior lamella and its homologous structures.