1 University of Adelaide, SA, 5005, Australia
2 South Australian Museum/ University of Adelaide
3 Museum National d'Histoire Naturelle, Entomologie, 45 rue Buffon, 75231 Paris, France
4 The University of Ballarat, P.O. Box 663 Ballarat VIC 3353
The Uchidanurinae are amongst the most spectacular of all Collembola. These springtails are unusual as most possess brightly coloured digitations (epidermal spine-like projections) on their dorsal and lateral surfaces and are among the largest springtails recorded world-wide. The subfamily is undoubtedly ancient – possibly of Gondwanan origin – but, despite being of considerable biogeographic and phylogenetic importance, evolutionary relationships among members of the subfamily remain unstudied. Compounding this problem, out of the morphological characters that are particularly important in the separation of new species of Uchidanurinae (i) the extent of development of abdominal lobes or digitations, (ii) pigmentation, and (iii) colour pattern, only the former character is phylogenetically informative, assuming that, within genera, development cannot regress or reduce. Conversely, pigmentation and colour pattern variation are morphological characters that cannot be reliably used for phylogenetic analysis in Collembola. Owing to difficulties associated with establishing the evolutionary significance of morphological differences among members of the Neanuridae, and the lack of phylogenetically informative morphological characters within Uchidanurinae, a molecular approach to resolving species relationships as well as biogeographic hypotheses for the subfamily is essential. The subfamily Uchidanurinae – the ‘giant’ springtails – consists of eight highly endemic genera in India, Vietnam and Malaysia, Micronesia, New Caledonia, eastern Australia, and New Zealand. Here we reconstruct phylogenetic relationships based on COI and 28S sequence data. Accordingly, these data were used to test biogeographic hypotheses relating to processes that promote biological diversification, and hence, speciation with a focus on levels of divergence among species from Australia, New Zealand and New Caledonia. Our data clearly indicates that there are several new species from all three regions and mitochondrial DNA calibration of speciation events throughout Australasia.