The remarkable group of tools was detected among the hunter-gatherer-fishers' archaeological materials of the Russian Plain central part dated 3500–2700 BC. The so-called ‘crooked items' were initially interpreted as ritual phallic depictions, but now after conducting the more detailed analysis of their morphology, technology and use-wear, there is no doubt that we deal with retouchers, used to perform the pressure flaking of flint. The most astonishing fact is that the straight parallel to these retouchers exists, coming from the opposite side of the globe, namely the Bering Sea region – Kamchatka, Chukotka and Alaska, where the same tools are known both in archaeological and ethnographical collections.

Sixteen elk antler retouchers and one wooden were found at the hunter-gatherer-fishers' settlements of Central Russia and North Belarus. At least three retouchers made of ivory (walrus tusk) were found at the settlements and in burials of Kamchatka and Chukotka dated the 1st mill AD. A bunch of retouchers is known from the Inuit ethnographical collections. It is an outstanding example of the convergent invention, but hypothetically, the presence of similar, probably more ‘profane' wooden retouchers, all over North Eurasia during the mid-Holocene can't be fully neglected. All pieces are carefully made, polished and usually have linear decoration at the handle. Fragmented items clearly witness the unintentional breakage, caused by the intensive pressure at the curve of the handle and lever junction, during the enhanced pressure flaking.

The elk antler and ivory were the most durable raw materials in forest and Arctic zones respectively. It seems, however, that the presence of wooden retoucher with use-wear traces, could point at the probable special meaning of at least elk antler retouchers, as in the Arctic zone the lack of appropriate wood caused the wider use of bone. The major lever form is tongue- or beak-shaped, but at six items from Central Russia is has the form of a sculptured swan (or sometimes, probably, goose) head. The special symbolic meaning of these tools, both with or without waterfowl head, is signified by some unusual finding contexts. They were deposited at the settlement zone either in the vicinity of burials (inside the so-called ‘ritual hoards', broken and/or burnt), ore inside cultural layers, intact, painted by ochre, seemingly reflecting the high social role of the skilled flint-knapping specialists.

The morphological similarity of elk-head staffs and swan-head retouchers, both crooked and made of elk antler, recalls the special role of elk and swan/waterfowl in mythology and cosmology of indigenous North Eurasian peoples, connected with notions of creation, procreation, seasonal calendar and well-being. The cosmological aspect was probably expressed by the special retoucher swan-handle, as the tool itself was literally used to create a new flint item.