Proto-Indo-Aryan language

Proto-Indo-Aryan (sometimes Proto-Indic) is the reconstructed proto-language of the Indo-Aryan languages. It is intended to reconstruct the language of the Proto-Indo-Aryans, who had migrated into the Indian subcontinent. Being descended from Proto-Indo-Iranian (which in turn is descended from Proto-Indo-European), it has the characteristics of a satem language.

History
Proto-Indo-Aryan is meant to be the predecessor of Old Indo-Aryan (1500–300 BCE), which is directly attested as Vedic and Classical Sanskrit, as well as by the Indo-Aryan superstrate in Mitanni. Indeed, Vedic Sanskrit is very close to Proto-Indo-Aryan.

Some of the Prakrits display a few minor features derived from Proto-Indo-Aryan that had already disappeared in Vedic Sanskrit.

Today, numerous modern Indo-Aryan languages are extant.

Differences from Vedic
Despite the great archaicity of Vedic, the other Indo-Aryan languages preserve a small number of conservative features lost in Vedic.

One of these is the representation of Proto-Indo-European *l and *r. Vedic (as also most Iranic languages) merges both as. Later, however, some instances of Indo-European again surface in Classical Sanskrit, indicating that the contrast survived in an early Indo-Aryan dialect parallel to Vedic. (A dialect with only is additionally posited to underlie Magadhi Prakrit.) However, it is not clear that the contrast actually survived anywhere in Indo-Iranian, not even in Proto-Indo-Iranian, as  is also found in place of original *r in Indo-Iranian languages.

The common consonant cluster kṣ of Vedic and later Sanskrit has a particularly wide range of Proto-Indo-European (PIE) and Proto-Indo-Iranian (PII) sources, which partly remain distinct in later Indo-Aryan languages:
 * PIE *ks, *kʷs, *gs, *gʷs > PII *kš > Middle Indo-Aryan kh-, -kkh-
 * PIE *dʰgʷʰ, *gʰs, *gʷʰs > PII *gʱžʱ > Middle Indo-Aryan gh-, -ggh-
 * PIE *tḱ; *ǵs, *ḱs > PII *tć, *ćš > Middle Indo-Aryan ch-, -cch-
 * PIE *dʰǵʰ, *ǵʰs > PII *ȷ́ʱžʱ > Middle Indo-Aryan jh-, -jh-