I finally got in the Russian-Siberian Tatar dictionary that I requested via interlibrary loan. It treats Siberian Tatar as a single language. Because there’s not much information about any of the Siberian Tatar varieties (Tobol-Irtysh, Baraba, Tomsk), this is a really valuable resource to have. I’ve created a new entry for a literary Siberian Tatar language with links to each of the varieties.
Thanks to this new resource, I’m up to 11,800 entries, and should have 12,000 very soon.
Standard Siberian Tatar looks a lot like standard Tatar, except that /č/ is /ts/ and the voicing distinction is lost at word boundaries. There’s a bit of confusion as to the origin of Siberian Tatar, but the fact that it looks so much like standard Tatar (especially in the vowel shift that occurred among the languages of the Ural-Volga region) suggests that it may represent an eastward migration. The language then would have mixed with local varieties of Turkic, losing the voicing distinction and the /č/ sound, and likely picking up some of the unique vocabulary we see in many of the dialects. Further research is needed to back up this hypothesis.