AbstractThe stop inventory of Witzapan Nawat, a critically endangered indigenous language of El Salvador, has been traditionally described as consisting only of a voiceless series /p t k kw/. In this paper, I measure the voice onset time, consonant duration, and percent voicing in stops produced by five L1 Witzapan Nawat speakers. I find that, while /p t kw/ have acoustic characteristics of voiceless stops in practically all contexts, the velar stop in this language is better analyzed as a voiced velar stop /ɡ/ rather than /k/. This results in an asymmetrical and unusual stop system that is not predicted by some theories of phonemic inventory structure. For instance, markedness-based theories propose that /ɡ/ is more marked that /b d/ and predict that, if a language has one voiced stop, it would be /b/ or /d/ rather than /ɡ/. On the other hand, feature-systemic models predict that, if a language has a stop with the [+voice] feature at a given place of articulation, it will also tend to have this feature in stops at other points of articulation to maximize feature economy. The phonemic inventory of Witzapan Nawat contradicts these predictions. I explain the asymmetrical stop inventory of this language as the result of diachronic developments involving sound change and analogy, concluding that language change does not necessarily advance towards symmetry and that phonemic inventories are the reflection of their diachrony, as proposed by Evolutionary Phonology.