The Family Vespertilionidae is the largest family of microchiropteran bats found the region with 49 formally recognised species. It is a likely the true level of species richness for this family is much higher due to the presence of a number of species that are probably an collection of sister taxa. An example of this so-called cryptic speciation is provided by the recent clarification of the taxonomic status of large-boded Nyctophilus species undertaken by Dr Harry Parnaby (2009).
Until recently, the family included as a sub-family the bent-wing or long-fingered bats (all in the genus Miniopterus) but this group is now considered a full family, the Miniopteridae. (For phylogenetic analyses supporting this change to traditional familial relationships see Agnarsson et al. 2011; Van Den Busshe and Hoofer 2004; Miller-Butterworth et al. 2007).
Multiple phylogenetic studies have also highlighted that the genus Myotis is distinctly different from other vespertilionids (Agnarsson et al. 2011; Roehrs et al. 2010). This is of rather limited interest in Australia and PNG because only one species (Myotis macropus) is thought to occur in the region.
Unfortunately, the new phylogenetic results are of limited use in understanding the place of other Australian and PNG vespertilionids in the evolutionary history of the group. This is because very little of the available gene sequencing used to create the latest phylogenetic trees include representatives of the endemic vespertilionid radiation within the region. What we can say is that multiple lines of evidence are suggesting that the Australian vespertilionid radiation (i.e. the genera Nyctophilus, Vespadelus, Chalinolobus, and Falsistrellus) are part of a clade that includes Hypsugo, Tylonycteris and Laephotis of south-east Asia, and Neoromicia and Vespertilio of Africa and Europe.