Catalogue of revised and new plant macrofossils from the Aquitanian-Burdigalian of Soma (W Turkey) – Biogeographic and palaeoclimatic implications

Abstract

The position of Turkey between Europe and Asia makes this region interesting for palaeobotanical investigations. We investigated plant macrofossils from early Miocene deposits of W Turkey (Soma, Manisa) and compiled a catalogue of revised and new plant taxa. We documented 100 fossil-taxa, of which several are new for Turkey (Mahonia aff. pseudosimplex, Ziziphus paradisiaca, Comptonia longirostris, Carya denticulata, Viscum, Fatsia, Pungiphyllum cruciatum). Some previous records are rejected (e.g. Apocynophyllum, Cassia, Castanea, Ficus, Illicium, Liriodendron, Vaccinium). Using modern ecology and taphonomy, we reconstructed palaeoenvironments. We found evidence for a belt of drier, more open habitats with cycads, Dracaena, Mahonia, Smilax miohavanensis, and others. Other vegetation units comprise swamp and riparian forest with few dominants (expressed in high abundance of leaf specimens). On well-drained soils, lowland forest with large-leaved Lauraceae vel Fagaceae and rare elements (Fatsia) was present, while humid temperate broadleaf-deciduous and conifer forest flourished higher up. To infer palaeoclimate we used the Climate Leaf Analysis Multivariate Program (CLAMP) and compared the results with other Miocene localities of Turkey. Early Miocene floras had warm climates (mean annual temperature, MAT, and coldest month temperature, CMMT) with weak precipitation seasonality. MAT and CMMT were cooler during the early middle Miocene. Several fossil-taxa at Soma have biogeographic links with older/coeval localities in C Europe and/or the W Mediterranean region (cycads, Torreya, Dracaena, Smilax miohavanensis, Mahonia aff. pseudosimplex, Carya denticulata, Ilex miodipyrena, Pungiphyllum). Few taxa have clear links to C Asian floras (Comptonia longirostris). True E Mediterranean endemics are even rarer (Mahonia spp., Quercus sosnowskyi).