A new genus for the eastern dwarf galagos (Primates: Galagidae)

The family Galagidae (African galagos or bushbabies) currently comprises five genera: Euoticus Gray 1872; Galago Geoffroy Saint-Hilaire, 1796; Galagoides Smith, 1833; Otolemur Coquerel, 1859; and Sciurocheirus Gray, 1872, none of which is regarded as monotypic, but some (Euoticus, Otolemur) certainly qualify as oligotypic. We argue that a sixth genus needs to be erected if the taxonomy is to reflect galagid evolution accurately. Genetic evidence has consistently demonstrated that the taxa currently referred to the genus Galagoides are not monophyletic, but form two clades (a western and an eastern clade) that do not share an exclusive common ancestor. We review 20 years of genetic studies, from allozyme electrophoresis through to DNA sequence analysis, that support this conclusion. Morphological evidence, however, is not entirely congruent with genetic reconstructions; parallel dwarfing in the two clades has led to convergences in skull size and shape that have complicated the classification of the smaller members of the clades. We present a craniodental morphometric analysis of small-bodied galagid genera that identifies distinguishing characters for the genera, and a comparison of loud call structures to support our proposal that five taxa currently subsumed under the genus Galagoides (Gs cocos, Gs granti, Gs orinus, Gs rondoensis and Gs zanzibaricus) be placed in their own genus, for which we propose the name Paragalago.