The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Haleakala-, Maui: Keystone of a hyperdiverse Hawaiian radiation

Abstract

The Mecyclothorax carabid beetle fauna of Haleakalā volcano, Maui Island, Hawai‘i is taxonomically revised, with 116 species precinctive to Haleakalā recognized, 74 newly described. Species are classified into 14 species groups, with the newly described species arrayed as follows: 1, Mecyclothorax constrictus group with Mecyclothorax perseveratus sp. n.; 2, Mecyclothorax obscuricornis group with Mecyclothorax notobscuricornis sp. n., Mecyclothorax mordax sp. n., Mecyclothorax mordicus sp. n., Mecyclothorax manducus sp. n., Mecyclothorax ambulatus sp. n., Mecyclothorax montanus sp. n., Mecyclothorax waikamoi sp. n., Mecyclothorax poouli sp. n., and Mecyclothorax ahulili sp. n.; 3, Mecyclothorax robustus group with Mecyclothorax affinis sp. n., Mecyclothorax anchisteus sp. n., Mecyclothorax consanguineus sp. n., Mecyclothorax antaeus sp. n., Mecyclothorax cymindulus sp. n., and Mecyclothorax haydeni sp. n.; 4, Mecyclothorax interruptus group with Mecyclothorax bradycelloides sp. n., Mecyclothorax anthracinus sp. n., Mecyclothorax arthuri sp. n., Mecyclothorax medeirosi sp. n., Mecyclothorax inconscriptus sp. n., and Mecyclothorax foveolatus sp. n.; 5, Mecyclothorax sobrinus group with Mecyclothorax foveopunctatus sp. n.; 6, Mecyclothorax ovipennis group with Mecyclothorax subtilis Britton & Liebherr, sp. n., Mecyclothorax patulus sp. n., Mecyclothorax patagiatus sp. n., Mecyclothorax strigosus sp. n., Mecyclothorax takumiae sp. n., Mecyclothorax parapicalis sp. n., Mecyclothorax mauiae sp. n., Mecyclothorax subternus sp. n., Mecyclothorax flaviventris sp. n., Mecyclothorax cordaticollaris sp. n., and Mecyclothorax krushelnyckyi sp. n.; 7, Mecyclothorax argutor group with Mecyclothorax ommatoplax sp. n., Mecyclothorax semistriatus sp. n., Mecyclothorax refulgens sp. n., Mecyclothorax argutulus sp. n., Mecyclothorax planipennis sp. n., Mecyclothorax planatus sp. n., and Mecyclothorax argutuloides sp. n.; 8, Mecyclothorax microps group with Mecyclothorax major sp. n., Mecyclothorax xestos sp. n., Mecyclothorax orbiculus sp. n., and Mecyclothorax contractus sp. n.; 9, Mecyclothorax scaritoides group with Mecyclothorax scarites sp. n., Mecyclothorax timberlakei sp. n., Mecyclothorax crassuloides sp. n., Mecyclothorax crassulus sp. n., Mecyclothorax gracilicollis sp. n., and Mecyclothorax dispar sp. n.; 10, Mecyclothorax haleakalae group with Mecyclothorax reiteratus sp. n., Mecyclothorax splendidus sp. n., Mecyclothorax bacrionis sp. n., and Mecyclothorax simpulum sp. n.; 11, Mecyclothorax vitreus group with Mecyclothorax kipwilli sp. n., Mecyclothorax kipahulu sp. n., Mecyclothorax kaumakani sp. n., and Mecyclothorax kuiki sp. n.; 12, Mecyclothorax montivagus group with Mecyclothorax rex sp. n.; 13, Mecyclothorax ducalis group with Mecyclothorax aquilus sp. n., Mecyclothorax invisitatus sp. n., Mecyclothorax longidux sp. n., and Mecyclothorax brevidux sp. n.; and 14, Mecyclothorax palustris group with Mecyclothorax hephaestoides sp. n., Mecyclothorax oculellus sp. n., Mecyclothorax bicoloris sp. n., Mecyclothorax bicol...

Cladistic classification of Mecyclothorax Sharp (Coleoptera, Carabidae, Moriomorphini) and taxonomic revision of the New Caledonian subgenus Phacothorax Jeannel

“…Only one of the 108 French Polynesian Mecyclothorax (Liebherr 2012(Liebherr , 2013 and one of the 239 Hawaiian Mecyclothorax (Liebherr 2015) are included. For New Guinea, 8 of the 22 species are represented.…”

Cladistic classification of Mecyclothorax Sharp (Coleoptera, Carabidae, Moriomorphini) and taxonomic revision of the New Caledonian subgenus Phacothorax Jeannel

“…Examination of illustrations of male genitalia for other New Guinean species (Baehr 1992(Baehr , 1995(Baehr , 1998(Baehr , 2002(Baehr , 2008(Baehr , 2014 indicates that the entire 22 species currently known from New Guinea belong to this subgenus. Phylogenetic placement of M. montivagus of Hawaii, and M. marau of Tahiti near M. punctipennis of Australia, the hypothesized colonist taxon for both the Hawaiian and Tahitian radiations (Liebherr 2013(Liebherr , 2015 indicates that these species appropriately act as surrogates for the entire 239 species of the Hawaiian Mecyclothorax radiation (Liebherr 2015) plus the 108 species comprising the Society Island radiation on Tahiti and Moorea (Liebherr 2012(Liebherr , 2013. The Australian Mecyclothorax fauna is shown to be biogeographically polyphyletic, with the Australian species M. lateralis, M. minutus, M. ambiguus, and M. punctipennis latecomers (Fig.…”

“…The positions of these setae are illustrated in Liebherr (2013: fig. 2) and Liebherr (2015: fig. 7).…”

“…This substitution results in the French Polynesian representative species being placed as adelphotaxon to the five species associated with M. ambiguus and M. punctipennis. However, given the subaerial geological history of Tahiti and the Hawaiian Island of Maui where M. punctipennis resides as the most generalized Hawaiian species (Britton 1948, Liebherr 2015, all evolution in this nexus of the cladogram (Fig. 7) has taken place within the last 1-2 Myr, the time of subaerial appearance of Tahiti Nui and Maui (1.4 and 1.8 Ma respectively; Hildenbrand et al 2004, Sherrod et al 2007).…”

“…Only phylogenetic analysis of Cyphocoleus plus a broad array of potential outgroups allowed such a hypothesis to be proposed. Conversely, immense disparity across an island radiation may evolve adaptively in isolated and restricted island situations over a very short time, such as with Mecyclothorax carabid beetles of the Society and Hawaiian Islands (Liebherr 2013(Liebherr , 2015. Characterizing such biological diversity is the first step toward hypothesizing the context within which a particular lineage has evolved.…”