Unrecognized Ant Megadiversity in the Australian Monsoonal Tropics: The <scp> <i>Meranoplus unicolor</i> </scp> Forel Complex

ABSTRACT The monsoonal (seasonal) tropics of northern Australia is a global center of ant diversity but is unrecognized as such because the great majority of its species is undescribed. Here, we document undescribed diversity in the Meranoplus unicolor Forel complex, which is formally recognized as a single species occurring throughout central and northern Australia. We obtained 80 CO1 sequences from specimens collected from throughout the taxon's range, and from these we recognize 42 species, 33 from the monsoonal zone. None of the species appears to be M. unicolor . Most of the species have very limited distributions and many are represented by single collections; given that no specimens are available for most of central and northern Australia, the total number of species in the complex is likely to be in the order of twice as many as we have recognized. Our findings provide further evidence that the ant fauna of monsoonal Australia contains several thousand species, which is many more than current estimates for any other regional fauna.