Cryptic diversity, diversification and vicariance in two species complexes ofTomocerus(Collembola,Tomoceridae) fromChina

Abstract

Springtails (Collembola) are a group of arthropods that are found in terrestrial ecosystems throughout the world. Two species complexes,Tomocerus ocreatusandT. nigruscomplexes, are widely distributed in the southern and northern parts of easternChina, respectively. There is a poor understanding of the species diversity within these complexes and of the factors affecting their diversification and dispersal. Species delimitation using a general mixedYule coalescent model and aBayesian multilocus approach recognized 22DNA‐based species. This supports the presence of extensive cryptic diversity in species that are geographically widespread. In addition to genetic differences, we discovered corresponding morphological differences in jumping organs among the major clades. Analyses of divergence times and historical biogeographical processes revealed thatocreatusandnigruscomplexes originated in southern and northernChina, respectively. We estimated their divergence at 27.8–44.9 Mya during theEocene–Oligocene, at the time when the transmeridionalQinling–DabieMountains uplifted and formed the north–south geographical boundary of easternChina. Diversification analyses suggest that the subsequent orogenesis of theQinghai–TibetanPlateau in westernChina had little impact on divergences within the two species complexes so that they maintained their geographical patterns from the Paleogene to the present day. Our findings also point to a potentially important influence of theQinling–Dabie Mountains on patterns of animal speciation and distribution inChina.