Palaeoenvironments of the Manych Valley at the End of Late Pleistocene Based on Rodent and Mollusk Data from Sanmanych (Rostov District, Russia)

A thorough consideration is given to the geological, palaeotheriological and malacological materials obtained from the Pleistocene Sanmanych locality, which is the only locality with mammal fauna in the Manych depression (46°24′53″ N, 42°36′25″ E). The brackish-water mollusk composition indicated that the bone-bearing series should be correlated to the Early Khvalynian transgression. The fossil record gives an insight into the palaeoenvironment at the time that the Caspian Sea water broke through the Manych depression into the Black Sea basin. The faunal evidence points to arid conditions and a cool climate. The rodent species composition is rather poor; it exclusively includes species indicative for an open environment, which suggests a wide spread occurrence of steppe and semi-deserts in the Manych valley during the Late Glacial (~16–12 ka BP).

The new data of fauna and landscapes history in the Manych basin during the late Pleistocene

The geology and mammal and mollusk fauna from the Late Pleistocene locality Sanmanych (the single location of paleontological remains in the Manych basin) in Rostov region are discussed. The received data permit to reconstruct the climatic-environmental condition during the Early Khvalynian transgression in the Manych basin. This transgression was dated by 14 C in the interval between 16–12 kyr BP. As a result of the formation of a Cascade of Eurasian Basins for the first time in the Late Pleistocene Caspian waters of the Khvalynian Sea had flooded to the Manych depression and the Manych-Kerch strait was originated during that time. The marine mollusks appeared in the Manych basin together with Caspian Sea water. The salinity of Khvalynian basin was close to the same of the Caspian Sea (10–12%) and the water temperature was lower than recent one, what confirms by the fact that mollusk’ shells were two-three times smaller than the modern ones of the same species. The analysis of the small mammal fauna permits to reconstruct the arid open landscapes during the formation of the location. The lower mammal diversity indicates the unfavorable climatic and environment conditions – the high aridity and the rather cool climate.