Oduda
8
Ultimately the Hyrkanians spread across the steppes until they reached the great inland sea (The Vileyet Sea). A group of them cross this sea and, while conquering the peoples on the other side and incorporating them into their own genetic makeup also decided to settle into the area as there were no more steppes to traverse on this side of the sea. They began building more permanent settlements and eventually cities and a great and powerful nation, Turan. However, they are still Hyrkanian and are consistently called such throughout the writings even though if you look at the society they are building it is the basis for what will become the Ottoman Turkic style (clearly not religious wise but architecture and clothing and such).
Now according to the Hyborian Age essay, at the end where he explains what happens when the Hyborian Age itself ends this is what Robert E. Howard has to say.
The Hyrkanians, retreating to the eastern shores of the continent, evolved into the tribes later known as Tatars, Huns, Mongols and Turks.
Since he has established on a consistant basis that the Turanians ARE Hyrkanian it is safe to say that they were on ones who evolved into the Turks. The Hyrkanian’s east of the Vileyet likely comprised the Huns, the Mongols and the Tartars but that is speculation (aside from the Mongols obviously which were the eastern most group of them). There is no reference to Russian or Russ specifically but also from the Eurasian steppes there is this.
Other clans of the Cimmerians adventured east of the drying inland sea, and a few centuries later mixed with Hyrkanian blood, returned westward as Scythians.
So again, the only group of people who really are constantly in that region, and who are the progenitors of most peoples on that area, are the Hyrkanians.