A preliminary phylogeny of Prosopistomatidae (Ephemeroptera) based on morphological characters of the larvae, and an assessment of their distribution

Abstract

Until recently, only four species of the monogeneric family Prosopistomatidae were described from the Afrotropical realm; one from Madagascar, and three from sub-Saharan Africa. Recent studies have revealed the family to be more diverse, with a further five species from Madagascar, one from the Comores archipelago and seven from sub-Saharan Africa, which are currently in the process of being formally described. This brings the total number of known species globally to 34. Phylogenetic analysis of morphological features of the larvae reveals that the type species, Prosopistoma variegatum Latreille, 1883, a Madagascan species, along with two other Madagascan species, belongs to a clade which is different to the majority of other Afrotropical species. It is more closely related to the European species, the species from the Middle East and several of the species from the Oriental and Australasian regions. One possible explanation is diversification of this ‘P. variegatum’ clade after Madagascar and India separated from Africa. The precursors of this clade may have been carried northwards on the Indian Plate, and subsequently dispersed to Europe, and to Australia via the Indo-Pacific islands. A concurrent dispersal of the now predominantly mainland African clade may have occurred and, in Madagascar and the Oriental realm, members of this group occur sympatrically with, or in close geographic proximity to, members of the ‘P. variegatum’ clade.