Oghur languages
The Oghur or Oğuric languages (also known as Bulgar, Pre-Proto Bulgaric, Hunno-Bulgarian, Hunno-Turkic, or Lir-Turkic and r-Turkic) are a branch of the Turkic language family. The only extant member of the group is the Chuvash language. Languages from this family were spoken in some nomadic tribal confederations, such as those of the Onogurs, Bulgars, and Khazars. Some scholars consider Hunnic a similar language.
History
The Oğuric language is part of Turkic language distinct from the Common Turkic. Today is represented only by Chuvash, while the Bulgar, and related Khazar, went extinct. There's no content among linguists on the relation between Oğuric and Common Turkic. There several issues without clear conclusion; if they are parallel branches of Proto-Turkic (3000-500 BC), which branch is more arhaic and which split up, was Oğuric a separate tongue, and did Oğuric represent Archaic Turkic before phonetic changes in ca. 100-400 AD.
Features
The Oğuric languages are also known as "-r Turkic" because the end consonant in relevant words is "*r", in contrary to "*z" in Common Turkic, thus the term Oğur in Oğuric and Oğuz in Common Turkic. Another specific shifts are: Com. "š" > Oğ. "l" (tâš - tâl; stone); "s" > "š"; "č" > "ś"; "k/q" > "ğ"; "y" > "j, ś"; "d,δ" > "δ - z (10th cent.), r (13th cent.)"; "ğd" > "z - r (14th cent.)"; "a" > "l (after 9th cent.)".