Relictual distributions in southern and East Africa: a “Khoisan fringe” in heelwalkers (Mantophasmatodea)
There are striking commonalities between the distribution and internal taxonomic structure of the newly-discovered insect order Mantophasmatodea (‘heelwalkers’) and that of the Khoisan languages, both consisting of four major lineages, one in East Africa and three in southern and south-western Africa. Nevertheless, within these regions, the two groups show rather different distribution patterns, most Mantophasmatodea species occurring along the Great Escarpment, while the majority of Khoisan languages are spoken further inland. The survival of these two ancient (each in its own time scale) groups in these regions is probably primarily due to distinctive yet relatively stable climatic conditions. I argue that finding such commonalities between fundamentally different groups can be a key factor in a more objective selection of global conservation hotspots, focusing on relictual distributions.