Since 2005 large-scale archaeological studies of unique Early Paleolithic sites known as
Aynikab I–IV; Mukhkai I, II; Gegalashur I–III have been conducted in Central (Inner) Dagestan. The sites were discovered by Kh.A. Amirkhanov, Corresponding Member of the Russian Academy of Sciences, in 2005–2006. They are located in the Akusha district, Republic of Dagestan. Geomorphologically, the sites are situated on the top of the watershed of the Akusha and Usisha streams. Their absolute elevation is 1,540–1,630 m above the sea level. In 2010–2014 main excavation activities were aimed to explore multilayer Aynikab I, Mukhkai I and II from different aspects. Important results were obtained during excavations of Mukhkai II. The excavations showed that the cultural layers of the site were sandwiched between Pleistocene deposits, which were 73 m thick. The test trench dug into the slope revealed 129 geological layers, with 35 layers containing archaeological lithic artifacts, including five layers that yielded bone remains of mammals. The cultural layers of the site have different thickness and genesis and differ in the types and abundance of finds. Stone tool industry at Mukhkai II has all characteristics typical for a classical Oldowan culture of the Early Paleolithic.
The study of the sites covers many aspects. Earth science methods have provided a lot of opportunities to obtain various data shedding light on the site dating, distinctive features relating to the entire layer of the site and its separate bands, specifics of natural and climatic conditions at the time of the site cultural by the earliest humans. These data include numerous paleozoological and paleobotanical remains, results of paleomagnetic, palinological, paleosoil, lithological and facies analyses.
Of special interest is the discovery of two sites in the Mukhkai II cultural layer in 2010 and 2012. These layers have revealed undisturbed habitats of prehistoric people buried in the ancient times. The sites are presently known as Mukhkai II, layer 80, and Mukhkai IIa. They are located at the depth of -33.5 and -38 m from the site soil surface. Stone tools made of flint (892 and 258 items, correspondingly) and mammal bone fragments (in total, around 1,800 pieces) have been recovered from several cultural layers at these sites. Stone artifacts include isolated choppers, nodules and knapped fragments, retouched tools, flakes, fragments and microchips viewed as material traces of past human activities. The spatial analysis of the cultural layers identified at both sites reveals a similar layout, which can enrich our understanding as to how the first Homo organized their economic activities and, probably, their habitation area. For example, prehistoric population settled at a site located on the bank of a small (around one meter wide) creek with slow-flowing or back water. Probably, this creek was a tributary (an oxbow lake, a meander) of a larger river or flew into a small lake. Two main sections have been detected in the cultural layers, i.e. an extended hollowed section on the creek bed and a waterside section. Both sections contain archaeological finds. The hollow on the creek bed is filled up with multiple bones of ancient mammals, i.e. remains of dismembered animal carcasses. Some bones have preserved marks left by human-induced splitting and flesh cutting. Presence of predator bones is suggestive of a fierce competition between man and carnivore for food resources. The assemblage of large animal bones contains remains of extinct early Pleistocene animals, both herbivore and carnivore. Faunal data are extremely important for dating the sites and along with pollen data help archaeologists reconstruct the environment at that time.
The studies of the Early Paleolithic in the North Caucasus performed over the past 10 years have provided undisputed evidence of pre-Acheulian sites in this region. Archaeological finds from the Central Dagestan sites have a worldwide importance and contribute substantially to the efforts aimed to address the issue of the earliest human settlement in the Near East, the Caucasus and Eastern Europe. The database of available sources demonstrates that prehistoric people arrived to the North Caucasus and Russian Plain South not later than two million years ago and populated this region throughout a greater part of the Early Pleistocene. The earliest population penetrated the region through the Caspian corridor, which stretched along the west maritime coast of the Caspian Sea.