In my post called “The Movements and Expansions of Indo-European Language Groups” – https://vellaunos.ca/2021/03/24/the-movements-and-expansions-of-indo-european-language-groups/ , I suggested that there was an Italo-Illyric group of languages that included the Italic languages (such as Latin, Oscan, Umbrian, etc.) and the Illyrian languages. I have since developed the view that the Illyrian languages were not only not closely related to the Italic languages, but that they were in fact derived from a form of Proto-Indo-European other than the Proto-Indo-European of the Yamnaya Culture.
A culture called the Sredny Stog Culture (c4500-c3500 BCE) developed in what is now Ukraine by about 4500 BC. Its origins seem to be in the Dnieper-Donets Culture (c5000-c4200 BCE) that preceded it in that region. The Dnieper-Donets Culture was related to the Samara Culture that developed on the Volga to the east by about 5000 BCE. The Khvalynsk (c4900-c3500 BCE) and Repin Cultures eventually developed from the Samara Culture, and the Yamnaya Culture (c3300-c2600 BCE) eventually emerged from the Khvalynsk and Repin Cultures.
The Suvorovo Culture (or Suvorovo Group) (c4500-c4100 BCE) of southwestern Ukraine, southern Moldova and eastern Romania may have been an early migration from the Khvalynsk Culture. Whereas the Suvorovo Culture had kurgans like the Khvalynsk Culture, the Dnieper-Donets Culture, the Sredny Stog Culture and the Cernavodǎ Culture did not. But the Suvorovo Culture seems not to have maintained itself nor to have migrated elsewhere or developed into any other culture – it seems to have been a dead end.
All of the cultures mentioned in the two preceding paragraphs probably spoke forms of a common language, this common language being a major dialect of Proto-Indo-European that I call South Proto-Indo-European (or Steppe Proto-Indo-European). The other major dialect of Proto-Indo-European was the North Proto-Indo-European (or Forest Proto-Indo-European) dialect spoken largely in the area of the Comb Ceramic Culture (or Pit-Comb Ware Culture) – this dialect being ancestral to the Balto-Slavic and Indo-Iranian languages, and partly contributing to the formation of the Germanic languages and of the Greek, Phrygian and Armenian languages.
It is probable that there were some notable differences between the western forms (Dnieper-Donets, Sredny Stog) and eastern forms (Samara, Khvalynsk, Repin) of South Proto-Indo-European. It was the eastern form of South Proto-Indo-European that was the language of the Yamnaya Culture, and that produced the Celtic and Italic language groups, as well as partly contributing to the formation of the Germanic languages and of the Greek, Phrygian and Armenian languages. But the western form is not without descendants…
By about 4000 BC (after the Suvorovo Culture), a culture called the Cernavodǎ Culture (c4000-c3200 BCE) appeared in what is now eastern Romania, replacing the Early European Farmer culture called the Karanovo Culture. According to the Wikipedia article on the Cernavodǎ Culture, its pottery and burials show similarities to those of the Sredny Stog Culture. It is quite likely that the Cernavodǎ Culture represents an expansion of the Sredny Stog folks westwards (perhaps following the example of the Suvorovo Culture).
By the way, I do not believe that the Cernavodǎ Culture had anything at all to do with the Anatolian languages. As I’ve explained before (https://vellaunos.ca/2022/01/06/the-non-indo-european-hittites/), I do not view the Anatolian group as originally Indo-European. Instead, I see it as an Indo-Europeanized group that developed in the Novotitorovka Culture (c3300-c2700 BCE) that existed in the northern Caucasus region adjoining the Yamnaya Culture, and that eventually migrated southwards into Anatolia around the eastern side (not the western side) of the Black Sea.
It appears that the Cernavodǎ Culture gradually expanded westwards through the northern Balkans, probably mixing considerably with the Early European Farmer groups of the region. A result of this western expansion of the Cernavodǎ Culture seems to be the Kostolac Culture of northern Serbia and western Romania. And a derivative of the Kostolac Culture was the Vučedol Culture (c3000-c2200 BCE) that covered most of the northwestern Balkans.
It seems likely to me that the Vučedol Culture was the original culture of the Illyrian peoples, and that the roots of the Illyrians therefore lie mainly in the Sredny Stog Culture. So, although the Illyrians were Indo-European, they weren’t Indo-European in the same way as the Yamnaya ancestors of the Celtic and Italic folks who passed by between c2900 and c2600 BCE. And it seems likely to me that the Albanian language, which is Indo-European but considerably unique compared to the other Indo-European languages, is descended from an Illyrian language.