Abstract
Docidiadia grimaldii sp. nov., the second known species in the genus, is described based on a holotype female and on a female paratype. The differences with D. burmitica Blagoderov & Grimaldi, the type-species of the genus, are discussed. The specimens allow the study of important details of the antenna, wing, and terminalia. The question of the connection of Docidiadia to the extant family Diadocidiidae is addressed. An antenna with the flagellum more slender towards the apex is also known in the extinct sciaroid family Archizelmiridae, but the wing venation of Docidiadia is much more conservative than the wing in archizelmirid genera.