Cystihalysites sp. and its significance to biostratigraphy and event stratigraphy in the Ludlow (Late Silurian) of Gotland, Sweden

Cystihalysites sp. from the Ludfordian Eke Formation on Gotland, Sweden, is the youngest halysitid coral found in Baltoscandia. Halysitids had earlier been considered as absent at this level and were thought to have disappeared in the Gorstian—lower Ludfordian Hemse Group. The new material indicates that at least one species survived the early parts of the Lau extinction event.