Since the 16th century the proto-Kamta community has fragmented giving rise to the differentiated modern lects.[6] The modern lects are:[7][8] Kamta (Assam and West Bengal), Rangpuri (Bangladesh), Rajbanshi (Nepal) and Surjapuri (Bihar).As a result, the KRDS lects became diglossic vernaculars to these standard varieties and acquired phonological and morphological features from them.[12] Nevertheless, two standards are emerging within the KRDS lects: a central Jhapa variety targeting speakers in Nepal, and an eastern Cooch Behar variety targeting speakers in northern West Bengal and western Assam.[13] The development of proto-Kamta (also called proto-Kamata) was the result of Sandhya, a ruler of Kamarupa Nagara (North Guwahati), Kamrup moving his capital[5] to Kamatapur and establishing the Kamata kingdom, thus carrying the native language along with.
The speakers are distributed unevenly, as shown in the map.
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The proto-languages of the eastern Magadhan languages. Kamarupa Prakrit corresponds to ?proto-Kamarupa here, a hitherto un-reconstructed proto-language. The period corresponds to earlier than 1250 CE, when proto-Kamta began to innovate unique features.
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