A new genus of Therevidae, Ambradolon, is diagnosed from Dominican amber. The type species, A. grimaldii, is described based on a single fossil male. Species of Therevidae possessing putative synapomorphies with A. grimaldii were identified. A cladistic analysis resolved three additional monophyletic genera. A new genus, Insulatitan, represented by four new species: I. romaynae, I. trishae, I. watsoni, and I. youngi and the described genera, Lindneria Kröber and Penniverpa Irwin & Lyneborg, were also shown to be monophyletic lineages. Lindneria was previously represented by a single species, L. splendida Kröber. Psilocephala platyptera Kröber is here placed in the genus Lindneria. Six new species of Lindneria are described: L. bellingeri, L. browni, L. dicosta, L. penelopae, L. thompsoni, and L. wintertoni. Psilocephala brunnipennis Kröber was recognized as belonging to the genus Penniverpa Irwin & Lyneborg and is so placed as a new combination.