The Yamnaya culture or the Yamna culture (, lit. 'culture of pits'), also known as the Pit Grave culture or Ochre Grave culture, was a late Copper Age to early Bronze Age archaeological culture of the region between the Southern Bug, Dniester, and Ural rivers (the Pontic steppe), dating to 3300–2600 BCE. It was discovered by Vasily Gorodtsov following his archaelogical excavations near Siversky Donets in 1901—1903. Its name derives from its characteristic burial tradition: (romanization: ) is a Russian adjective that means 'related to pits ()', as these people used to bury their dead in tumuli (kurgans) containing simple pit chambers. The people of the Yamnaya culture were the result of a genetic admixture between the descendants of Eastern European Hunter-Gatherers (EHG) and people related to hunter-gatherers from the Caucasus (CHG), an ancestral component which is often named "Steppe ancestry", with additional admixture of up to 18% from Early European Farmers. Their material culture was very similar to the Afanasevo culture, and the populations of both cultures are genetically indistinguishable. They lived primarily as nomads, with a chiefdom system and wheeled carts and wagons that allowed them to manage large herds. The people of the Yamnaya culture are also closely connected to Final Neolithic cultures, which later spread throughout Europe and Central Asia, especially the Corded Ware people and the Bell Beaker culture, as well as the peoples of the Sintashta, Andronovo, and Srubnaya cultures. Back migration from Corded Ware also contributed to Sintashta and Andronovo. In these groups, several aspects of the Yamnaya culture are present. Genetic studies have also indicated that these populations derived large parts of their ancestry from the steppes. The Yamnaya culture is identified with the late Proto-Indo-Europeans, and the Pontic-Caspian steppe is the strongest candidate for the Urheimat (original homeland) of the Proto-Indo-European language. Origins Yamnaya culture was defined by Vasily Gorodtsov in order to differentiate it from catacomb and srubnaya cultures that existed in the area but considered to be of later period. Owing to the historical distance of Yamnaya culture, and reliance on archaeological findings, debate continues as to its origin. In 1996 Pavel Dolukhanov suggested that the emergence of the Pit-Grave culture represents a social development of various local Bronze Age cultures, representing "an expression of social stratification and the emergence of chiefdom-type nomadic social structures", which in turn intensified inter-group contacts between essentially heterogeneous social groups. According to ,