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

Abstract

The family Galagidae (African galagos or bushbabies) 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 and Otolemur) certainly qualify as oligotypic. We argue for the recognition of a sixth genus, 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 that corroborate this conclusion. Further, we compare vocalizations emitted by small-bodied galagids with proposed phylogenetic relationships and demonstrate congruence between these data sets. 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 species. We present a craniodental morphometric analysis of small-bodied galagid genera that identifies distinguishing characters for the genera and supports our proposal that five taxa currently subsumed under Galagoides (Galagoides cocos, Galagoides granti, Galagoides orinus, Galagoides rondoensis and Galagoides zanzibaricus) be placed in their own genus, for which we propose the name Paragalago