Waters, Saskia2019-02-222019-02-221990https://hdl.handle.net/10539/26454A DISSERTATION SUBMITTED TO THE FACULTY OF SClENCE, UNIVERSITY OF THE WITWATERSRAND, JOHANNESBURG, FOR THE DEGREE OF DOCTOR OF PHILOSOPHY.An assemblage of Cretaceous, Diptera, recovered from the sediments of the Orapa Diamond mine, Botswana, is described. The fossil Diptera are placed In the following families: Tipulidae, Empididae, Hybotidae, Bibionidae, and possibly the Mycetophilidae, Rhagionidae and Anisopodidae. A new pulid species, Helius botswanensis (Tipulidae, subfamily Limoniinae), is described; it is the oldest representative of the subfamily. (Abbreviation abstract)enDiptera, Fossil.Paleontology -- Botswana -- Orapa.Paleontology -- Cretaceous.Thesis