The Family Miniopteridae was, until Miller-Butterworth et al.'s (2007) conclusive review of the evidence, included as a sub-family of the Vespertilionidae. Questions had been raised for many decades about the true phylogenetic position of the group, and several phylogenies had shown the group to warrant recognition as a family (e.g. Van Den Busshe and Hoofer 2004). Using only morphological evidence was not enough to make a definitive statement about the place of the family in the Chiropera. Molecular phylogenetic methods have now added the missing evidence to show that, although clearly part of the broader group of microchiropteran bats, the Miniopteridae should be considered a distinct clade and raised to full family status.
However, the most interesting evidence comes from the latest phylogenetic trees for the Chiroptera (Agnarsson et al. 2011; Roehrs et al. 2010) which places the Miniopteridae as a sister group to the entire South American phyllostomid radiation. There is much to be done regarding the phylogeography of this enigmatic group, but there is the hint of a Gondwanic origin. The (at present) circumstantial evidence comes from the fact that, together with the equally enigmatic family Mystacinidae (endemic to New Zealand), the Miniopteridae could represent a west Gondwana fauna radiating into Africa, Australia and New Zealand, and the phyllostomids an east Gondwana fauna. This idea is lent support by the presence of fragmentary mystacinid fossils from early to mid-Miocene deposits (about 23 to 15 million years ago) in Australia (Hand et al. 1998). It is also intriguing to note that two recent studies lend some weak support to this rough phylogeographic hypothesis: Miniopterus in Europe appears to be the result of a recent post-glacial expansion and differentiation (Furman et al. 2010), and the origin of major groups within the passeriform birds (which have been recognized for some time as gondwanic in origin) occurred in the early to mid-Cretaceous. Could Gondwana have been the place in which some early elements of the Microchiroptera radiated and then dispersed? This all rather speculative at the moment, but it is nevertheless an interesting possibility and something to motivate further study.
The bent-wing or long-fingered bats (all in the genus Miniopterus) are represented in the Australian and PNG region by 6 species, although much work is still needed to understand the full level of species-level diversity in the genus. This is a major challenge that has been a work in progress for almost 150 years! Molecular methods are beginning to reveal the true complexity of this group and we can now indicate that distinct sub-species exist within Australia for the most challenging species, Miniopterus schreibersii (Appleton et al. 2004; Cardinal and Christidis 2000; Rheinhold et al. 2000). The species also exhibits geographical variation in skeletal morphology (Wilson 2008) and echolocation call parameters (Conole 2000).