In antiquity, Dacian, Greek, Illyrian, Messapic, Paeonian, Phrygian and Thracian were the Paleo-Balkan languages which were attested in literature.
Paleo-Balkan studies are obscured by the scarce attestation of these languages outside of Ancient Greek and, to a lesser extent, Messapic and Phrygian.
A Palaeo-Balkanic or Balkanic Indo-European branch has been proposed in recent research, comprising the Albanoid or Illyric (Albanian-Messapic), Armenian, and Graeco-Phrygian (Hellenic-Phrygian) subbranches.
[1] Τhe common stage between the Late Proto-Indo-European dialects of Pre-Albanian, Pre-Armenian, and Pre-Greek, is considered to have occurred in the Late Yamnaya period, after the westward migrations of Early Yamnaya across the Pontic–Caspian steppe; also remaining in the western steppe for a prolonged period of time, separated from the Indo-European dialects that later gave rise to the Corded Ware and Bell Beaker cultures in Europe.
[2] Due to the processes of Hellenization, Romanization and Slavicization in the Balkans, the only surviving representatives of the ancient languages of the region are Greek and Albanian.
The centum or satem character of Illyrian is difficult to detect due to the paucity of the available 'Illyrian' linguistic material and to the dual nature of its interpretation.
[39][40][41] Armenian Greek Phrygian(extinct) Messapic(extinct) Albanian While "Paleo-Balkan" languages are conventionally understood as a linguistic areal grouping, in recent historical linguistic research scholars propose a distinct "Balkanic" (or "Paleo-Balkanic") Indo-European branch based on shared Indo-European morphological, lexical, and phonetic innovations, as well as shared lexical proto-forms from a common pre-Indo-European substratum.
[46][47] The word for "goat" is a remarkable common proto-form of non-Indo-European origin exclusively shared between Albanian, Armenian, and Greek.