On Kunama ukunkula 'elbow' and its proposed cognates in Nilo-Saharan languages

There have been two attempts at reconstructing proto-Nilo-Saharan (pNS), yet they diverge widely. To illustrate the lack of consensus even at the level of cognate recognition among NS languages, I selected the Kunama word ukunkula “elbow” and found it to be included by several scholars in different etymologies which poorly overlap. One major disagreement bears on whether ukunkula consists of a unique duplicated stem or is a compound word. Ukunkula is often considered cognate with Songay haηkoro ( honkoro ) and Berta k'oηk'oloη “elbow”. I propose here that ukunkula is unrelated and that the real Kunama cognate of the Songay and Berta nouns is ikoηkoro - “to bend”. I could not find convincing cognates of ukunkula or ikoηkoro - in Shabo and the Kadu family, likely affiliated to NS. Nevertheless, I present some other unpublished potential cognates between Shabo, Kadu and NS that may strengthen the case for a genetic relationship among them.