Review of Mecyclothorax Sharp (Coleoptera: Carabidae: Moriomorphini) from Papua New Guinea, with Descriptions of Five New Species

2018

DEZ

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The 15 species of Mecyclothorax Sharp precinctive to New Caledonia are revised and shown by cladistic analysis to comprise a monophyletic lineage, here treated as subgenus Phacothorax Jeannel. The New Caledonian species of subgenus Phacothorax include Mecyclothorax fleutiauxi (Jeannel), M. najtae Deuve, and 13 newly described species: M. jeanneli sp. n., M. laterobustus sp. n., M. laterorectus sp. n., M. laterosinuatus sp. n., M. laterovatulus sp. n., M. manautei sp. n., M. megalovatulus sp. n., M. octavius sp. n., M. paniensis sp. n., M. picdupinsensis sp. n., M. plurisetosus sp. n., and two jointly authored species; M. kanak Moore & Liebherr sp. n., and M. mouensis Moore & Liebherr sp. n.. Subgenus Phacothorax is one of five subgenera recognized within genus Mecyclothorax based on cladistic analysis of 65 exemplar taxa utilizing information from 137 morphological characters. The four other monophyletic subgenera include the precinctive Australian Eucyclothorax subgen. n. (type species Mecyclothorax blackburni [Sloane]), the precinctive Queensland Qecyclothorax subgen. n. (type species Mecyclothorax storeyi Moore), the precinctive New Zealand Meonochilus Liebherr & Marris status n., and the geographically widespread and very diverse nominate subgenus, distributed from St. Paul and Amsterdam Islands, eastward across Australia and New Guinea, and in the Sundas, Timor Leste, Lord Howe and Norfolk Islands, New Zealand, and the Society and Hawaiian Islands. The biogeographic history of Mecyclothorax can be derived from the parsimony cladogram time-calibrated by times of origin of particular geographic areas inhabited by resident representative species. Based on sister-group status of subgenus Phacothorax and subgenus Mecyclothorax, and occupation of Lord Howe Island-an island originating no earlier than 6 Ma-by the earliest divergent lineage within subgenus Mecyclothorax, the ancestor of present-day Phacothorax spp. is hypothesized to have colonized New Caledonia 6 Ma, subsequent both to Cretaceous Gondwanan vicariance as well as any Oligocene submergence. Area relationships among the New Caledonian Phacothorax point to earliest diversification incorporating the northern massifs, and most recent diversification on the ultramafic volcanic substrates in the south of Grand Terre. Flight wing loss has played an important role in shaping the various island faunas, both in their morphology as well as their diversity. The retention of flight capability in only a few of the many hundred Mecyclothorax spp. is presented in light of how populations evolve from macropterous colonizing propagules to vestigially winged specialists. Interspecific differences in genitalic structures for the sister-species pair M. fleutiauxi + M. jeanneli are shown to involve functional complementarity of male and female structures. Extensive geographic variation of male genitalia is demonstrated for several New Caledonian Mecyclothorax spp. This variation deviates from the geographically uniform male genitalia exhibited by species in the hy...

Section: Mecyclothorax Genitalic Evolutionmentioning

confidence: 67%

Section: Mecyclothorax Historical Biogeographymentioning

confidence: 80%

Section: Resultsmentioning

confidence: 99%

Section: Mecyclothorax (Eucyclothorax) Peryphoides (Blackburn)mentioning

confidence: 99%

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

2018

DEZ

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“…1A-B). Subgenus Mecyclothorax, by far the most diverse component of the genus with over 350 species included (Liebherr 2013(Liebherr , 2015(Liebherr , 2017(Liebherr , 2018, is represented in mainland Australia by only four species; the adelphotaxa M. lateralis and M. minutus, and the more widespread species M. ambiguus and M. punctipennis. This subgenus diversified first in New Guinea, with species from Lord Howe and Norfolk Islands, and Borneo cladistically derived from that grade (Fig.…”

Section: Cladistic Analysismentioning

confidence: 99%

Taxonomic review of Australian Mecyclothorax Sharp (Coleoptera, Carabidae, Moriomorphini) with special emphasis on the M. lophoides (Chaudoir) species complex

2018

DEZ

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The Australian fauna ofMecyclothoraxSharp (Coleoptera: Carabidae: Moriomorphini) is reviewed, with special focus on species assigned to the monophyletic subgenus Eucyclothorax Liebherr:M.isolatus,sp. n.from Western Australia,M.mooreiBaehr,M.punctatus(Sloane),M.curtus(Sloane),M.blackburni(Sloane);M.eyrensis(Blackburn);M.peryphoides(Blackburn);M.darlingtoni,sp. n.from Queensland;M.jameswalkeri,sp. n.from Western Australia;M.lophoides(Chaudoir); andM.cordicollis(Sloane). The last six species listed above–theM.lophoidesspecies complex–have been the source of long-term confusion for taxonomists, with male genitalic characters providing trouble-free species circumscription. One new subspecies,M.lewisensisestriatus,subsp. n.from Queensland is added to the seven previously described taxa of the monophyletic subgenus Qecyclothorax Liebherr. The balance of the fauna consists of four species in the subgenus Mecyclothorax:1and2, the sister-species pairM.lateralis(Castelnau) andM.minutus(Castelnau);3,M.ambiguus(Erichson); and4,M.punctipennis(MacLeay).Mecyclothoraxfortis(Blackburn),syn. n., is newly synonymized withM.minutus.MecyclothoraxovalisSloane is recombined asNeonomiusovalis(Sloane),comb. n., and a neotype is designated to replace the destroyed holotype. Phylogenetic relationships for the AustralianMecyclothoraxare proposed based on information from 68 terminal taxa and 139 morphological characters. The biogeographic history of AustralianMecyclothoraxis deduced based the sister-group relationship betweenMecyclothoraxand theAmblytelus-related genera, with both groups hypothesized to have originated during the late Eocene. Diversification withinMecyclothoraxhas occurred since then in montane rainforests of tropical Queensland, temperate forest biomes of the southwest and southeast, and in grasslands and riparian habitats adjacent and inland from those forests. Several species presently occupy interior desert regions, though no sister species mutually occupy such climatically harsh habitats. TheM.lophoidesspecies complex exhibits profound male genitalic diversification within the context of conserved external anatomy. This disparity is investigated with regard to the functional interaction of the male internal sac flagellum and female spermathecal duct. Though limited association of flagellar and spermathecal duct configurations can be documented, several factors complicate proposing a general evolutionary mechanism for the observed data. These include:1, the occurrence of derived, elongate spermathecal ducts in three species, two of which exhibit very long male flagella, whereas males of the third exhibit a very short flagellum; and2, a highly derived and exaggerated male flagellar configuration shared across a sister-species pair even though the two species can be robustly diagnosed using external anatomical characters, other significant genitalic differences involving male parameral setation, and biogeographic allopatry associated with differential occupation of desert versus forest biomes.

Phylogenetic placement of the Australian Pharetis, gen. nov., and Spherita, gen. nov., in a revised classification of the circum-Antarctic Moriomorphini (Coleoptera : Carabidae)

2020

Invert. Systematics

The carabid beetle tribe Moriomorphini attains a disjunct austral geographical distribution, with member taxa occupying Australia, New Zealand, New Caledonia, the Sundas, southern South America and Polynesia. The group arose in Australia, the area exhibiting the greatest generic diversity for the tribe. In this contribution, two new genera are added to the Australian fauna. Pharetis thayerae, gen. nov., sp. nov., is described from Grenvillia, New South Wales, and Spherita newtoni, gen. nov., sp. nov., is described from Avon Valley National Park, Western Australia. Their phylogenetic placement within the tribe is accomplished by parsimony analysis based on 208 morphological characters across 124 taxa, 114 in-group species and 10 outgroup taxa representing Trechini, Psydrini and Patrobini. Nearly all polytypic moriomorphine genera are represented in the analysis by at least two exemplars, allowing initial tests of generic monophyly. A revised classification is proposed for Moriomorphini, with subtribal clades related as (Amblytelina + (Moriomorphina + Tropopterina)). The Western Australian genus Spherita is placed as adelphotaxon to Sitaphe Moore, a genus restricted to tropical montane Queensland. From the phylogenetic analysis, other non-contemporaneous east–west Australian disjunctions can be inferred, as well as multiple trans-Tasman area relationships between eastern Australia and New Zealand, all proposed to be of Miocene age. Pharetis exhibits a disjunct, trans-Antarctic relationship with Tropopterus Solier, its sister-group, distributed in southern South America. Alternative vicariance-based and dispersal-based hypotheses are discussed for the origin of Tropopterus. A review of the taxonomic development of the tribe illustrates the signal importance of monotypic genera in elucidating biological diversity.