The development of zl in Tibetic languages

This article assesses five proposals for the development of Tibetic zl , which has modern reflexes including Lhasa Tibetan /_(ⁿ)d/. My assessment considers on their ability to account for zl ’s modern reflexes, their plausibility from the perspective of phonetics, and their congruence with typological observations. I conclude that, at present, Bialek (2018)’s proposal is the most plausible. However, future research may produce comparative evidence that support Gong (2016)’s proposal. At the end, I outline a methodology for investigating the role of functional load in Tibetic consonant cluster mergers.