Monodanthura is a new genus of the family Anthuridae (Crustacea: Isopoda: Anthuridea) closely related to Notanthura Monod, 1927. The new species M. maroccana proves that Notanthura is not synonymous with Haliophasma Haswell, 1881. ”Cyathura” liouvillei Monod, 1925, is closely related to the new species and belongs to the new genus Monodanthura.