The Baltic Middle Silurian stromatoporoid succession

Although a remarkable number of regional taxonomical and biostrat igraphical paper s has been published on the Silurian stromatoporoids during last decades , there does not still exist a formal zonal stromatoporoid standard for any region. The Baltic area offers good opportunities for elaborating such a standard for stromatoporoid stratigraphy due to relatively detailed researches covering Silurian outcrop areas on both sides of the Baltic Sea (Riabinin, 1951; Nestor, 1964, 1966, 1970; Nestor, 1979; Mori, 1968, 1969, 1970, 1978) . The aim of the present paper is to summarize the existing data on the distribution of stromatöporoids in the Baltic middle Silurian (Wenlock). The main attention is paid to the species distributed both in the East Baltic and Gotland sequences.