Miocene siliceous microfossils from the open cast coal mine Gračanica (Bugojno paleolake, Bosnia and Herzegovina) and their significance: a preliminary report

The Langhian (middle Miocene) marls of lacustrine succession cropping out in the open cast coal mine Gracanica (Bugojno basin, central Bosnia and Herzegovina) yielded a rich siliceous microfauna. The most common are sponge spicules (megascleres), less common are diatoms and chrysophyte cysts. Cell wall remains of a green alga Botryococcus sp. were often observed in one sample. The most common spicules are spinose oxeas that strongly resemble the...