A new species of the highly specialized hemipteran family of social ectosymbionts, the Termitaphididae, is reported in Miocene amber from the Dominican Republic: Termitaradus avitinquilinus, n.sp. It differs from the only other fossil termitaphidid (Termitaradus protera Poinar and Doyen), in Miocene Mexican amber, and from modern species by various distinctive features. Two of the three specimens of T. avitinquilinus are preserved in a piece of amber with its presumed host, a worker of the basal termite, Mastotermes electrodominicus Krishna and Grimaldi. The hypothesis that the family Termitaphididae is ancient and inhabited Pangaea is disputed in favor of a much more recent, Tertiary origin. It is suggested, in fact, that termitaphidids are highly modified Aradidae, possibly derived from Mezirinae.