Dr. Harvey E. Mayer, February 1999:
800 Pennsylvania Avenue 23
Beaumont, CA 92223-2460
"... It is my linguistics based theory that the ancient Thracians and  Dacians were Balts. (See my LITUANUS articles, “Balts and Carpathians” (1997) 43:2. 22-30; “South Baltic” (1996) 42:2. 60-70; and “Dacian and  Thracian as southern Baltoidic” (1992) 38:2. 24-30.) Evidence for this is the following.

    1. The 373 Dacian-Thracian-Baltic roots discussed by Duridanov.
    2. The fitting of special Dacian and Thracian features (which I identified from Duridanov’s listings) into Baltic isogloss patterns so that I identified Dacian and Thracian as southeast Baltic. South Baltic because, like Old Prussian, they keep unchanged the diphthongs ei, ai, en, an (north Baltic Lithuanian and Latvian show varying percentages of ei, ai to ie, and en, an to  (to ) in Lithuanian, to ie, uo in Latvian). East Baltic because the Dacian word uvete (now in Rumanian spelled juvete) has , not z as in west Baltic, and the Thracian word pušis (the Latin-Greek transcription shows pousis which, I believe, reflects -š-.) with zero grade puš- as in Lithuanian pušìs rather than with e-grade *peuš- as in Prussian peus. Zero grade in this word is east Baltic, e-grade here is west Baltic, while the other word for “pine, evergreen”, preid (Prussian and Dacian), priede (Latvian), is marginal in Lithuanian matched by no *peus- in Latvian.

So Dacian and Thracian are south Baltic like Prussian and east Baltic like Lithuanian (but not like Latvian which is west Baltic like Prussian).

In LITUANUS (1992) I say that Dacians brought (as slaves) Carpathians south who became Messapians and Illyrians and from these, Albanians, and north who became Slavs. My LITUANUS (1993) article, “Slavic, a balticized Albanian”, 39:2. 78-83, also discusses linguistic relations between Baltic and Slavic.

The LITUANUS (1997) article also describes the non-Dacian Rumanians as a Carpathian people who quickly romanized linguistically to gain Roman support against their Baltic masters (the Dacians)."

In a second letter from March 2, 1999, Dr. Mayer added:

... I consider the Messapian not linkable to the Balts, but to the Slavs, Albanians, Illyrians, and Non-Dacian autochtonous Rumanians (=not Romans), that is, Caprathian peoples, linguistically.