Dialectal tone description enhances historical tonology

This paper illustrates that in-depth descriptive work of closely related varieties of Dinka, a Nilotic tone language with an unusually complex suprasegmental system, provides solutions to previously unanswered questions about historical tone change. Using data from six dialects, I show the directions and mechanisms of tone splits and mergers. In-depth descriptive work combined with comparison allows innovation and novel discoveries from both synchronic and diachronic perspectives. These are also powerful tools for historical tonology and may ultimately shed light on the origins of tonal phenomena with previously opaque historical perspectives.