A new fossil cerambycid species, namely Plectromerus tertiarius nov. sp., included in amber of Dominican Republic (Early Miocene) is described.

The belonging to the genus Plectromerus Haldeman, 1847, today especially widespread in the West Antilles, and the relationship with current species are discussed.

Furthert observations and a key about this genus are added.

(in English with Spanish summary)