General description:
The most distinctive feature of this genus is the metathoracic process, a finger-like process arising between the hind coxae and projecting rearwards.
The term rudder has been adopted for this feature in order to create a clear connection between the vernacular name and the appearance of the fly (Sumner, 2018)
The feature was described by Andersson, 1989 as the "fulcrum". This same term however was used by Merritt & James (1973) to describe a different structure in the male terminal genitalia of Compsobata.
Taxonomic name: