Labial-velar to labial sound changes in Luto

Proto-Sara-Bongo-Bagirmi labial plosives became labial fricatives (*P > F) in boththe Nduga and Luto dialects of the Luto language. Subsequently, labial-velar plosives became labial plosives (*KP > P) in the Luto dialect, but were retained in theNduga dialect. This study adds to the growing literature on the labial-velar to labial change *KP > P (Cahill 2024 [this volume]). In addition, the occurrence of *P > F and the nonoccurrenceof *KP > P in the Nduga dialect provides evidence that the chain shift wasa pull chain rather than a push chain.