Philcarneum Allsopp & Hutchinson, 2023

Allsopp, Peter G. & Hutchinson, Paul M., 2023, Philcarneum new genus and Constricticollis new genus, two distinctive rhinoceros beetles (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini) from opposite sides of Australia with a revised key to the Australian dynastine genera, Zootaxa 5351 (3), pp. 322-340 : 323-325

Philcarneum Allsopp & Hutchinson , new genus urn:lsid:zoobank.org:act:627F2014-380F-41BA-BA4E-4EA153B3A274

Type species. Philcarneum aenigma Allsopp & Hutchinson new species, here designated.

Description of female. Body 13.0–14.0 mm long. Mentum not dilated and not concealing the bases of the maxillary palps, not compressed to form a thin, vertical lamina. Mandibles not visible from above beyond clypeus, not toothed, evenly rounded on outer edge. Maxillary palps elongate, longer than labial palps; galea strongly toothed, without a conical process terminating in a pencil of setae. Antennae with 9 antennomeres, apical 3 antennomeres forming a lamellate club, lamellae widest at middle, club not greatly enlarged and shorter than shaft, scape not expanded nor wedge-like, not concealing funicular antennomeres. Head and pronotum without armature or without head flattened vertically. Clypeus with anterior margin slightly concave in middle, not strongly contracted towards apex with sides concave; clypeofrontal suture straight, largely obliterated on lateral thirds, shallow groove across the middle. Anterior of pronotum with a conspicuous furrow set back from slightly raised and darker strip along the margin, glabrous. Elytral striae, including the sutural stria, indicated by indistinct lines of shallow punctures. Hind wings fully developed. Propygidium not enlarged, without stridulatory bands. Apical pygidial ridge glabrous. Postcoxal process forming a vertical columnar process. Last abdominal ventrite with semicircular excavation near the apex enclosing a somewhat membranous area. Protibiae bidentate, apical tooth broadly rounded. Metafemur and metatibia markedly broad and strongly compressed. Apical face of mesotibia setose; apex of metatibia truncate, slightly scalloped, without cilia, with 2 spurs. Metatarsomere 1 not produced apically. Claws symmetrical.

Male. Unknown.

Etymology. Named for Phillip Broughton Carne (1921–1989), the doyen of Australian dynastine studies. The name is neuter in gender.

Comments. Carne (1981) documented the presence in coastal southern New South Wales of females of an undescribed dynastine with markedly broad and strongly compressed metathoracic legs and with unusual characters of the antennomeres and the structure of the clypeus and maxilla. These indicated to him that it was generically distinct from other Australian Dynastinae , and he thought that it might be an exotic species. However, we cannot match it with any described species in Endrődi (1985) or in subsequent publications. Roger-Paul Dechambre (Muséum National d’Historie Naturelle, Paris; cited in Carne 1981) considered it to represent a genus closely similar in morphology to Calicnemis Laporte, 1832 , a genus that occurs on the western coasts of France, Spain and Portugal and coastal areas of the western Mediterranean ( Verdugo & Drumont 2015; Ben Aba & Bouragaoui 2021).

The species is known from three localities over about 70 km along the southeastern coast of New South Wales ( Carne 1981). The first was collected in 1905, with subsequent collections in 1968 and 1979. Only females have been collected and in late January and March. One was noted as walking on the surface of sand dunes towards dusk. Carne (1981) suggested that the modified metathoracic legs are similar to those of Calicnemis species and species of the New Zealand genus Pericoptus Burmeister, 1847 ( Ratcliffe & Orozco 2009, and references therein), both genera associated with coastal sandy tracts, and may provide leverage for emerging adults. Curiously, males have not been collected, despite the area being favoured by Canberra-based entomologists for summer and Easter holidays; presumably, they are not attracted to light and live away from forested areas that might be favoured collection localities.

Placement. The Australian dynastine fauna is arranged in six tribes ( Weir et al. 2019), with the majority of genera and species in the Pentodontini and fewer in the Dynastini, Oryctini, Oryctoderini, Phileurini and the introduced Cyclocephalini. Neither the Central and South American Agaocephalini nor the Madagascan Hexodontini ( Endrődi 1985; Smith 2006) has been recorded; the former have horns or tubercles on the head and pronotum, whilst the latter are distinguished by their nearly circular body shape, both unlike Philcarneum . Use of the key to Australian dynastine genera of Weir et al. (2019) to place Philcarneum is difficult as that key is mainly based on males. However, some characters of the female point to a likely placement.

The Australian Cyclocephalini is represented by one introduced species ( Allsopp & Hutchinson 2019; Weir et al. 2019); this has mandibles extending beyond the clypeus and with the apices upturned, and the metatibiae not enlarged.

The Dynastini, Oryctini and Oryctoderini can be excluded as are all much larger (> 20 mm long), the Dynastini also usually have mandibles excised at the apex and metatarsomere 1 of both sexes cylindrical, and the Oryctoderini also have the clypeus truncate and upturned or with 1–4 teeth. Similarly, the Phileurini can be discounted as the mentum of Philcarneum is not strongly dilated, the frons does not have tubercles or horns, the metafemora are thickened, and the transverse carinae of the meso- and metatibiae are not overly developed.

There remains the Pentodontini, a group where the mentum is narrowed towards the ligula, the postcoxal process forms a vertical columnar process, and the mesothoracic and metathoracic legs have small claws; all characters found in Philcarneum . Weir et al. (2019) arranged the Australian fauna in four subtribes (Cheiroplatina, Dipelicina, Pentodontina and Pseudoryctina) that provide a convenient classification, although this has not been applied to the worldwide Pentodontini, e.g., Endrődi (1985). Philcarneum does not conform to three of these subtribes:

• Pseudoryctina—the mentum is not compressed, the mandibles and labrum are not exposed beyond the clypeus, and the labrum does not have a deeply truncate face and is not at a considerable angle to the plane of the frons.

• Dipelicina—the protibiae are not simply tridentate, each apical labial palpomere is not securiform, the clypeus is not truncate, and the propygidium is not enlarged.

• Pentodontina—the mandibles are not toothed and are not visible beyond the clypeus, the ocular canthi are setose, the clypeus is not narrowed or truncate and the anterior margin is not bisinuate or bidentate, and the clypeofrontal ridge is not bituberculate.

The Cheiroplatina are recognised ( Carne 1957; Weir et al. 2019) by: mandibles evenly rounded distally, often concealed beneath the clypeus; antennae not sexually dimorphic; ocular canthi usually setose; clypeofrontal ridge transverse or posteriorly arcuate, often giving rise to a median tubercle or horn, never to paired armature; pronotum sometimes unarmed but more often with impressions or excavations; claws of male protarsi rarely asymmetrical; propygidium without a stridulatory area, apical pygidial ridge usually setose; terminal abdominal ventrite with a semicircular excavation near the apex enclosing a somewhat membranous area. Where known these characters are shared with Philcarneum .

Within the Cheiroplatina, Philcarneum is distinct from other Australian genera as it has the conspicuously flattened and broadened metafemurs and metatibiae and because from:

• Novapus Sharp, 1875 or Trissodon Burmeister, 1847 as the clypeus is not strongly contracted towards the apex and with the sides concave, and the mandibles are not exposed beyond or beside the clypeus.

• Cheiroplatys Hope, 1837 as the pronotum does not have any indication of a horn or depression, and metatarsomere 1 is not widened, flattened and with a distinct longitudinal carina externally.

• Semanopterus Hope, 1847 as there is no indication of a tubercle or low horn on the head, the clypeus does not have the anterior margin upturned, the galea are strongly toothed, the mandibles are not exposed beyond the clypeus, and there are no anterior or posterior foveae on the pronotum.

• Neodasygnathus Carne, 1957 or Dasygnathus MacLeay, 1819 as the body <17 mm long, there is no tubercle or horn on the head, the base of the mentum is not hollowed or cleft, the galea are strongly toothed, and the pronotum does not have an anteromedian impression and tubercle.

• Adoryphorus Blackburn, 1889 , Anomalomorpha Arrow, 1908 , Enracius Dechambre, 1999 or Erbmahcedius Hutchinson & Allsopp, 2021 as the elytra are not conspicuously guttered, and the galea do not have a small conical process terminating in a pencil of setae.

Although resembling the western Mediterranean Calicnemis species, Philcarneum differs most significantly in having nine antennomeres rather than eight, the protibiae with rounded and not pointed teeth, the galea with strong teeth, and the combined upper clypeus and frons with coarse, concentric sculpturing. Both sexes of the two species of Calicnemis are well known and well characterised ( Verdugo & Drumont 2015).

Philcarneum differs from the five known species of Pericoptus in having a rounded apex of the clypeus (not truncate and with two upturned teeth), nine antennomers (not 10), the protibiae with two teeth (not three), and its smaller size (not> 16 mm long). It also differs from another ‘mysterious’ monotypic genus Carneiola Endrődi, 1974 , described from three females from ‘Neu Seeland’ ( Endrődi 1974, 1985) but not known from New Zealand ( Watt 1984). That species has a triangular clypeus with the apex bidentate, 10 antennomeres and tridentate protibiae, although the head is strongly and transverse wrinkled, the mesotibiae and metatibiae are not broad and strongly compressed, and the elytra are coarsely punctate with dense rows of annulate punctures ( Endrődi 1985).

Philcarneum also bears resemblance to the two known species of Podalgus Burmeister, 1847 , P. cuniculus Burmeister, 1847 with five subspecies occurring across north Africa to northwestern India and P. nazarovi Gusakov & Legezin 2016 from southwestern Iran ( Endrődi 1985; Gusakov & Legezin 2016). It differs in having nine antennomeres (not 10), the protibia with two teeth (not three), the clypeus with the anterior margin slightly concave in the middle and not strongly contracted towards the apex (not triangular), the pronotum without strong, dense punctures, the elytral striae indicated by indistinct lines of shallow punctures (not with strong punctures as on the pronotum), and differently shaped metatibiae and metatarsi without ciliae on the truncate face (compare Gusakov & Legezin 2016, figs. 1–5).

These similarities with Philcarneum may simply reflect their similar habitats (sandy areas).