Monteithocanthon Gunter & Weir

Gunter, Nicole L. & Weir, Thomas A., 2017, Two new genera of Australian dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) with the description of six new species and transfer of six described species, Zootaxa 4290 (2), pp. 201-243 : 223

Monteithocanthon Gunter & Weir , new genus

Type species. Lepanus arator ( Matthews, 1974)

Etymology. Named in honour of Geoff Monteith for his contribution to the taxonomy of Australian dung beetles.

Diagnosis. Small, total length 2.1–3.2 mm. Elytra with 8 striae, 7 on disc and one on edge of epipleura ( Fig. 7 A). Seventh elytral striae obsolete ( Fig. 7 A). Pygidium with transverse groove at the base not reaching basal angle ( Fig. 9 ). Head without basal carina. Dorsal parts of eyes narrow, 2–5 facets wide; narrowest at base of head; eye canthus dividing or nearly dividing eye. Antennae with 3-antennomere club with club antennomeres of approximately equal width. Protibiae of male with comb of stiff setae and ventral brush of setae at inner apex; apical spur small, inconspicuous ( Fig. 7 C–D). Protibiae with 3 teeth on outer edge, not equidistant with apical 2 slightly closer together; serration between teeth and proximal to them ( Fig. 7 D–F). Each tooth has 1 group of setae dorsally ( Fig. 7 D). Distal edge of protibiae straight and trochantofemoral anterior pit absent ( Fig. 7 B). Trochanter excavated dorsally for reception of inner apical edge of protibia. Protarsi with 5 tarsomeres, tarsomere 5 the longest. Metatarsomere 1 wider than 2–5, metatarsomere 2 equal to tarsomere 5 in length ( Fig. 7 J). Male mesotibiae with dense setae on inner edge ( Fig. 7 I). Claws toothed ( Fig. 7 C). Male metatibiae generally bent with an extension but almost straight in M. peckorum ( Fig. 8 ). Mesometasternal suture procurved to strongly procurved. Mesepimera impunctate. Aedeagus with parameres asymmetrical, right paramere apically bent downwards and more-or-less expanded apically as in Fig. 9 . Hind wings fully developed, reduced, or absent.

Remarks. Matthews (1974) retained the genus Lepanus for practical purposes noting that adhering to a strict generic concept in such a morphologically diverse genus would lead to fragmentation into several small, difficult groups. All species of Monteithocanthon share many morphological affinities with Lepanus so it is unsurprising that M. arator and M. glaber were originally described within the genus Lepanus . A new genus is established here primarily on the basis of genetic results, with the two Monteithocanthon species sequenced to date always distinct from the clade containing the majority of Lepanus species. The phylogenetic grouping and the establishment of a new genus are supported by morphology. The six species assigned here to Monteithocanthon share a number of morphological features in combination, although many of these diagnostic characters are also individually found in other Australian ‘deltochiline-like’ genera and species.

Distribution. The genus is known only from Australia. Four species occur in northern Queensland primarily in the Wet Tropics, one species is distributed at high altitude in southeastern Queensland, and one species in southeastern Western Australia ( Fig. 5 ).

Figures

FIGURE 5. Distributional maps of species belonging to the new genera Matthewsius and Monteithocanthon including close up insets of A, Pilbara region, Western Australia; B, northeastern Queensland; C, southeastern Queensland; D, southwestern Western Australia; E, southeastern South Australia; F, central to southeastern New South Wales.

FIGURE 7. Key characters of Monteithocanthon new genus, all scale bars 0.25 mm. A, lateral view of elytra (M. arator); B, ventral view of profemur, note the absence of trochantofemoral anterior pit and presence of ornamentation on apex of protibia (M. arator); C, close up of ornamentation on apex of protibia, arrows pointing to comb and brush of setae (M. arator); D, dorsal view of male protibia with three tibial teeth each with only one group of setae dorsally (M. arator ♂); E, ventral view of male protibia (M. arator ♂); F, dorsal view of female protibia, note the apical spur is long and narrow (M. arator ♀); G, view of narrow anterior margin of lateral lobe of mesoventrite (M. arator); H, dorsal view of male mesotibia (M. arator ♂); I, ventral view of male mesotibia (M. arator ♂); J, male metatibia (M. arator ♂); K, view of broad anterior margin of lateral lobe of metaventrite (M. koombooloomba).

FIGURE 8. Male metatibia of species of Monteithocanthon new genus, all scale bars 0.25 mm. A, Monteithocanthon arator new combination; B, M. elliotensis new species; C, M. glaber new combination; D, M. koombooloomba new species; E, M. paraarator new species; F, M. peckorum new species; G, female metathoracic leg of M. arator.

FIGURE 9. Pygidium and aedeagus (left view, dorsal view, right view) of species of Monteithocanthon new genus. Scale bars of pygidium 0.5 mm, scale bars of aedeagus 0.2 mm. A, Monteithocanthon arator new combination; B, M. elliotensis new species; C, M. glaber new combination; D, M. koombooloomba new species; E, M. paraarator new species; F, M. peckorum new species.