Late Miocene (Early Turolian) vertebrate faunas and associated biotic record of the Northern Caucasus: Geology, palaeoenvironment, biochronology

Late Miocene continental deposits overlying the Khersonian marine sediments near the city of Maikop bordering the Belaya River (North Caucasus) yielded a diverse biotic record including palynology, ostracods, fresh-water and terrestrial molluscs, fishes, amphibians and reptiles, birds, and mammals. The obtained data indicate predominantly wooded landscapes along the banks of a large fresh-water estuarine or lagoonal basin with occasional connection with the sea. The basin existed in a warm temperate to subtropical climate with a high humidity and an estimated mean annual precipitation above 800 mm. The mammalian assemblage with Hipparion spp., Alilepus sp., Paraglirulus schultzi, Eozapus intermedius, Parapodemus lugdunensis, Collimys caucasicus sp. nov., Neocricetodon cf. progressus, etc. is referable to the early Turolian, MN 11. The data regarding composition and stage of evolution of the small mammal content combined with mostly normal polarity of the fossiliferous deposits, and the age estimates of the upper Khersonian boundary as between 8.6 and 7.9 Ma indicate a plausible correlation with Chron C4n and an age range between 8.1–7.6 Ma.