This Old World family is represented by only one genus, Rhinolophus, which is immediately recognisable by its intricate noseleaf. This complicated organ consists of several parts, including the sella, connecting process and lancet (Figure 97), all of which are useful in identifying the species. All members of this family have broad wings, allowing them to manoeuvre through cluttered habitats such as dense vegetation (Hill and Smith 1984). Echolocation is highly evolved with high duty-cycle calls that typically exhibit a constant frequency (HD-CF) component. The CF component differs between species and may be used as a guide to their identification (Monadjem et al. 2007, Webala et al. 2019). Morphological differences between species, especially those of similar size, are subtle. The principal diagnostic characters include skull and noseleaf characters. The noseleaf is important in the emission of the echolocation signal. Some 35 species are known from Africa, of which 22 occur in southern Africa. At least three taxa (R. darlingi, R. swinnyi and R. hildebrandtii) comprise sibling species that have now been split (Jacobs et al. 2013, Taylor et al. 2012, 2018a). Other taxa, such as R. fumigatus, still require taxonomic investigation that may unearth further cryptic species. The global review of this family by Csorba et al. (2003) listed 71 species of Rhinolophus; however, the recent review of the genus in the Handbook of the Mammals of the World (Csorba et al. 2019) lists 109 species, indicating just how poorly this group is known.

A recently published partial phylogeny of Rhinolophus (Demos et al. 2019b) appeared as revisions to this book were near completion. Invoking their new genetic data, these authors argue that several species recognised in this book are not genetically distinguishable from each other. However, the lineages questioned in their phylogenetic trees suffer from inadequate nodal support, and also highlight the influence of possible introgression between some populations. It is further unclear whether they sampled topotypical populations (Demos et al. 2019b). Most seriously, Demos et al. (2019b) did not use an integrative taxonomic method, as they only examined genetic relationships of the southern African rhinolophids that are known to be sympatric and/or distinguishable on morphological and sonar characters (Taylor et al. 2012, 2018a). Further work is required to establish the species boundaries within the southern African representatives of Rhinolophus (see further comments under Systematic Notes for R. eloquens).