Spanish is characterized by number concord in determiner phrases (DPs) and predicate nominals; the plural marker /s/ is attached to all relevant elements in a plural DP. Exceptions to this rule usually involve phonetically motivated processes of /s/-weakening in coda position, and do not result in a functionally different system of plural marking. A distinct pattern is found in two isolated dialects of Spanish spoken in ethnically cohesive Afro-descendent communities where Spanish was originally acquired as a second language by speakers of African languages. In both varieties, characterized by the absence of /s/-reducing phenomena, plural /-s/ tends to be marked only on the first element of plural DPs, usually a determiner. In one of the dialects, spoken in Ecuador, these “stripped plurals” alternate with full multiple plural concord, similar to vernacular Brazilian Portuguese. In the other dialect, spoken in Bolivia, stripped plurals appear to be a recent development, emerging from a more restructured traditional variety in which plural /-s/ was not used at all. A variational analysis of both dialects finds little evidence for spontaneous drift away from canonical multiple plural marking, but rather suggests an evolution from earlier contact-induced interlanguages that exhibited even less systematic plural marking. The appearance of Afro-Hispanic stripped plurals is tentatively correlated with the shift from a depleted definite article system to a configuration more closely resembling modern Spanish. A similar set of circumstances may have contributed to the formation of stripped plurals in vernacular Brazilian Portuguese.