The study od abundant microfauna of foraminifers and microflora of Dasycladacea enables a detailed division of Middle Triassic exposures in Central Eubea. Aegean-Bithynian, Pelsonian, Illyrian and Early Ladinian characteristic assemblages have been documented. Typical sedimentation produced on the new-formed internal platform. In the Anisian time the sedimentation was interrupted because of unstable conditions. The basin is isolated from the open sea and the formations of the hypersaline environment are deposited.