Savannas languages  The Savannas languages, also known as Gur–Adamawa (Adamawa–Gur), is a branch of the Niger–Congo languages that includes Greenberg's Gur and Adamawa–Ubangui families. The Gur–Adamawa link was demonstrated in Kleinewillinghöfer (1996) and has been accepted as established by later researchers, who have gone further in noting that the Adamawa and Gur languages themselves do not form coherent groups and are not necessarily more closely related internally than they are to each other. Bennett (1983) had also mentioned a "North Central Niger-Congo" branch consisting of Gurunsi, "Ubangian", and Trans-Benue groups, with the "Trans-Benue" group consisting of the Burak-Jen (i.e., Bikwin-Jen), Yungur (i.e., Bena-Mboi), and Tula-Longuda subgroups. There are several clusters of Adamawa languages; among the Gur languages, only the core of that proposal (Central Gur) has been retained, though it is possible that some of the 'peripheral' languages may turn out to be related to each other. Kleinewillinghöfer et al. (2012) note that a reconstruction of proto-Central Gur noun classes needs to include several Adamawa families. Senufo (ex-Gur) and Fali (ex-Adamawa) are excluded from Savannas, as they appear to be some of the more divergent branches of Niger–Congo. Dimmendaal (2008) excludes the Ubangian family from Niger–Congo altogether, stating that it "probably constitutes an independent language family that cannot or can no longer be shown to be related to Niger–Congo (or any other family)," though the Ubangian languages are themselves not a valid group, and the Gbaya branch may turn out to be related to Gur. Apart from such exceptions, Dimmendaal notes that the Savanna languages "can be shown to be genetically related beyond any reasonable doubt. The evidence is not only lexical in nature, it is based primarily on a range of cognate grammatical morphemes." Roger Blench (2012) considers Gur-Adamawa to be a language continuum (linkage) rather than an actual coherent branch. Kleinewillinghöfer (2014) notes that many "Adamawa" languages in fact share more similarities with various (Central) Gur languages than with other Adamawa languages, and proposes that early Gur-Adamawa speakers had cultivated guinea corn and millet in a wooded savanna environment.