In 1963,
Joseph Greenberg added them to the
Niger–Congo family, creating his Niger–Kordofanian proposal. The Kordofanian languages have not been shown to be more distantly related than other branches of Niger–Congo, however, and they have not been shown to constitute a valid group. Today, the
Kadu languages are excluded, and the others are usually included in Niger–Congo proper.
Roger Blench notes that the Talodi and Heiban families have the
noun class systems characteristic of the
Atlantic–Congo core of Niger–Congo but that the two Katla languages have no trace of ever having had such a system. However, the Kadu languages and some of the Rashad languages appear to have acquired noun classes as part of a
Sprachbund rather than having inherited them. Blench concludes that Talodi and Heiban are core Niger–Congo whereas Katla and Rashad form a peripheral branch along the lines of
Mande.
Heiban,
Katloid, and
Talodi are also grouped together in an automated computational analysis (
ASJP 4) by Müller et al. (2013). However, since the analysis was automatically generated, the grouping could be either due to mutual lexical borrowing or genetic inheritance. . Kordofanian includes
Kadu and all of the
Niger–Congo branches. == Talodi–Heiban languages ==