Distribution and palaeoecology of charophyte floras in Devonian coastal environments of the Central Taurides (Turkey)

Abstract

Pinnoputamen erikfluegeli and Sycidium aff. volborthi magnum from Akkuyu (Southern Taurides) are the first Palaeozoic charophytes reported from Turkey, and their presence emphasises the world-wide distribution of Sycidiales during the Middle and Upper Devonian. Both species occur in the upper part of the Akkuyu Section of late Givetian through early Frasnian age, based on combined biostratigraphical data. The sedimentary sequence mainly consists of reefal limestones and silt-/sandstones, partly intercalated with shales. In these nearshore deposits, charophytes and open marine fossils, notably brachiopods and conodonts, are found associated. With reference to identical primordial structures of vegetative and reproductive organs both in extant and Palaeozoic forms, and account taken of the prerequisite environmental conditions (such as salinity, light intensity, and nature of substratum), the mode of life in Palaeozoic charophytes was certainly similar to that of modern ones. By a critical review of other fossil occurrences interpreted as marine, we conclude that an allochthonous origin is most probable for the charophytes of the Akkuyu Section.