Abstract
In northeastern Europe, fossil freshwater diatom assemblages are known from several interglacial horizons. According to the Pleistocene stratigraphic scheme of the East-European Platform, the duration of the Pleistocene is 800 Kyr. The most ancient assemblages studied are from early Pleistocene deposits (Giinz-Mindel, more than 600 Kyr). Here a diverse and abundant flora (more than 440 taxa in total) occurs, including some extinct species. Middle Pleistocene assemblages (Riss, 400-130 Kyr) are known from two horizons, where a diverse flora (about 350 taxa) including rare extinct species is reported. Upper Pleistocene assemblages (Riss-Wiirm, 110-80 Kyr) are also diverse (more than 390 taxa) and include rare relics. All assemblages are generally similar with minor distinctions depending on their environment.