Stigmadiscus

Stigmadiscus Rasetti, 1966, is a genus of Lower Cambrian Eodiscinid trilobite belonging to the family Weymouthiidae Kobayashi Order Agnostida It lived during the Botomian stage, = late Lower Cambrian Stage 4 ; the upper Botomian Stage boundary corresponds to base of both the Middle Cambrian Wuliuan stage and Miaolingian Series.
Stigmadiscus resembles Acidiscus in having a relatively short glabella, distinct S1 and S2 lateral furrows, and a slender occipital spine. In fact, according to Cotton & Fortey consensus is that Stigmadiscus and Bolboparia Rasetti, 1966, are sister taxa of Acidiscus.