In the eastern part of Europe, from the Carpathians in the west to the Caucasus in the south and the Volga River in the east, a number of sites have yilded lithic assemblages with bifacial leaf points and bifacial asymmetric knives, dating from OIS 7 to OIS 5 and representing the Early Middle Palaeolithic (EMP) Leaf Point industry. The results of technological analyses indicate that the flaking technology in these EMP assemblages is not aimed at production of either laminar or Levallois blanks from prepared cores, despite the assemblages often contain a significant number of cores that can be classified as recurrent or preferential Levallois cores, using formal typological definitions. This eastern "anomaly" should prompt us to rethink the existing division between prepared and unprepared cores, taking in mind that similar types of cores may appear in different phases of their reduction within very different flaking technologies. The eastern "anomaly" also should prompt us to reformate the analysis and definition of knapping products and flaking technologies in the Lower and Middle Palaeolithic contexts, pointing to that the modern approach should be based on a comprehensive research of technological relationships between the core reduction sequence and the blank production sequence.
At present, the sites of the Upper Paleolithic of the Caucasus with an age ranging from 25–23 to 12–10 ka cal BP it is proposed to single out a separate period – the Epipaleolithic, by analogy with the Near East. This article summarizes data on the appearance of geometric microliths in the Epipaleolithic of the Caucasus and traces their changes during three main stages. The study is based on stratified assemblages with radiocarbon dates. The problem of appearance and spread of geometric microliths in the Upper Paleolithic of the Caucasus is considered in comparison with adjacent regions. A review of the Epipaleolithic industries of the Caucasus and adjacent territories (the Levant, Zagros, Anatolia, northeastern Azov Sea region, and Crimea) shows a variegated picture of the appearance of various forms of such forms in these regions. The current data unambiguously indicate that at the early stage of the Epipaleolithic geometric microliths are known only in the Levant and the South Caucasus. Based on the published data, it is possible to analyse the distribution of some forms. For example, scalene triangles are identified in the Near East and the South Caucasus at all stages of the Epipaleolithic. The earliest appearance of proto trapezes is noted in the Kebarian at the early stage of the Levantine Epipaleolithic. In the South Caucasus, according to current data, they are known only in the late stage of the Epipaleolithic. In the North Caucasus, trapezes are found starting from the middle stage of the Epipaleolithic. In Crimea, trapezes are characteristic of the late stage of the Epipaleolithic. In the North- Eastern Azov Sea region trapezes are absent, but parallelograms are represented. Segments are the most common form in all regions. The shape and nature of the processing of the segments may differ. The composition and diversity of geometric microliths could change at the sites within the same cultural area. This is clearly seen in the regions that are well studied and where there are known many sites having different economic specialization. Various methods of the attaching of geometric microliths to the shaft have provided the advantage of this type of tool. The modularity of such compound tools made it possible to increase the efficiency of making projectile weaponry. It is this advantage that facilitated distribution of geometric microliths in the Epipaleolithic over wide areas.
The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far northeast Asia) and Eastern Beringia (northwest North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation and vegetation, impacting faunal community structure and demography. While these palaeoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyse mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal carnivorans that dispersed into North America during the Pleistocene. Our results reveal striking synchronicity in the population dynamics of Beringian lions and brown bears, with multiple waves of dispersal across the Bering Land Bridge coinciding with glacial periods of low sea levels, as well as synchronous local extinctions in Eastern Beringia during Marine Isotope Stage 3. The evolutionary histories of these two taxa underline the crucial biogeographical role of the Bering Land Bridge in the distribution, turnover and maintenance of megafaunal populations in North America.
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