"It seems that two groups, possibly lineages or clans, were using Oleneostrovskii Mogilnik. This is evident from two spatial clusters within the cemetery: the northern cluster is associated with moose sculptures (fig. 2) and the southern cluster with snake and human effigies. The snake and human representations seem to be combined into a single zooanthropomorphic tradition, different from the northern group, whose identity was symbolized by moose representations. Thus, two separate populations shared the use of Oleneostrovskii Mogilnik. The northern cluster was used by people with northern European and Uralic features, more indigenous to the area, while the southern area was used by people with southern European and Siberian features, who might have been newcomers to the area. This interpretation underlines the genetic heterogeneity of the people who used the cemetery. Rather than supporting the existence of two distinct, non-communicating groups, these graduated differences in appearance and genetic makeup instead may reflect "unimpeded gene flow" across the forest zone of eastern Europe, brought about by long-distance travel, intermarriage, and partner exchange that was usual among the northern hunter-gatherer populations."
http://what-when-how.com/ancient-eu...glacial-foragers-80004000-b-c-ancient-europe/
So apparently in the same little island lived two different cultural spheres, with different set of physical features, using the same burial ground.
1 "Uralic"+Northern European
2 "Siberian"+ Southern European