A new species of Cheironitis van Lansberge, 1875 from Jordan (Coleoptera, Scarabaeidae, Onitini)

Abstract Background The genus Cheironitis van Lansberge, 1875, currently contains 23 species from the Old World. During a survey for dung beetles in Jordan, specimens of an undescribed species were collected at the historical site of Petra. New information A new species of Cheironitis (C.petraensis sp. n.) is described from the historical site of Petra, Jordan, illustrated and compared with its most closely related species. This new species is reminiscent of the African species of Cheironitis living in savannahs and could represent a relictual species of the mid-Holocene climatic optimum.


Introduction
The genus Cheironitis van Lansberge, 1875, currently contains 23 species from the Old World, including 13 in Palaearctic and 10 in Afrotropical Regions (Anonymous 2021).
While surveying dung beetles in Jordan in July 2012, the first author collected specimens of an undescribed species of dung beetle from horse dung at the historical site of Petra. This species belongs to a group of fulvous-coloured species, characterised by rows of smooth and shiny black tubercles on the elytra, including C. asbenicus Gillet, 1909, from southern Sahara, C. scabrosus (Fabricius, 1776, from south-eastern Africa, C. muelleri Janssens, 1943, from eastern Africa andC. socotranus Gahan, 1909, from Socotra Island , Bezdek 2016, Janssens 1937, Janssens 1943). This species is described here as new and compared with its most closely related species.

Materials and methods
Dry specimens and dissected structures were observed using a Bresser Advance ICD10-160X microscope. Illustrations were made using a Canon EOS 6D Mark II, coupled with a Canon EF 100mm f/2.8L Macro USM and a Macro Ring Lite MR-14EX. Images were stacked using Helicon Focus software.

Taxon treatment
Cheironitis petraensis Coppo, sp. n.  (Fig. 1c). Dark brown with lighter sides on fresh specimens, with dark brown bristles. Prosternal protrusion straight and slightly forked apically. Mesoventrite with short tubercle. Metaventrite granulate and pubescent laterally, with a slight medial groove along mid-line. Pygidium. Shagreened, aciculate, with brown patches (Fig. 1d). Legs. Outer surface of femora and tibiae yellow ochre; inner surface dark brown. Profemora display a short tooth at the antero-inferior edge proximally (Fig. 1e). Protibiae straight and not curved inwardly before middle. Distance between basal and second tooth shorter than between remaining teeth; anteroventral edge with four teeth, the proximal and distal ones short, the median one longer. Metafemora elongate, posterior edge with strong outwardly curved tooth medially. Mesofemora, meso-and metatibiae normal. Aedeagus. Phallobase as long as parameres. Parameres notched at proximal third; ventral border straight to the distal edge ( Fig. 1f -h).  (Fig. 1b). Larger. Head black, except for a patch of yellow-ochre on posterior surface of gena (Fig 1 -b'); clypeal surface coarsely granulose. Tubercle of the frontal carina stout. Metaventral groove less pronounced. Pygidium punctuated. Pronotum and elytra as in the male. Legs black. Femora unarmed. Protibiae unmodified.
Etymology. This new species is named after the place where it was collected, i.e. Petra historical site.

Distribution.
To date, this species is only known from Petra historical site, Jordan.

Analysis
Cheironitis petraensis sp. n. shows a stout outwardly curved long tooth medially on the posterior edge of hind femur, which is neither observed in C. scabrosus, C. asbenicus, C. muelleri nor in C. socotranus. The new species is close to C. socotranus by the distinct pronotal punctation of the elytral disc, the mesotibia without strong protrusion on the outer edge and the protibia straight on the basal two-thirds. Conversely, C. socotranus differs from the new species by several characters: underside of protibia with a row of numerous small teeth, with a much longer tooth in the middle; basal tooth of the outer edge of protibiae distinctly separated from the others; strong metaventral granulation; median coxae with a bifurcated, lamellar protrusion; the frontal tubercle of the male head distinctly behind the frontal carina; tibia with greenish reflection. Cheironitis scabrosus, C. asbenicus and C. muelleri differ from the new species by the indistinct pronotal punctures with coalescent points; by protibiae curved from the mid-length; by the presence of a strong protrusion on the inner border of protibiae and a strong and long protrusion on the outer edge of the mesotibiae. As with C. socotranus, they show also a different armature on underside of the protibiae, including a strong tooth, except in C. asbenicus where there is no tooth. Cheironitis petraensis, C. asbenicus and C. muelleri have the two basal external teeth of the protibiae slightly separated from the two apical teeth, the four teeth being equally separated in C. scabrosus.