3 Systematic Palaeontology.
Order: Coleoptera Linnaeus, 1758
Series: Staphyliniformia Latreille, 1802
Superfamily Staphylinoidea Latreille, 1802
Family: Staphylinidae Latreille, 1802
Subfamily: Paederinae Fleming, 1821
Tribe: Pinophilini Nordmann, 1837
Subtribe: Pinophilina Nordmann, 1837
Genus: Afrinophilina gen. nov.
Type species: Afrinophilina orapa species nov., by monotype and present designation.
Etymology: The generic epithet is a combination of Afri-, from ‘Africa’, and nophilina, from subtribe suffix ‘Pinophilina’.
Composition : Only type species Afrinophilina orapa species nov.
Diagnosis: The new species is placed in Paederinae using the following diagnostic characters of the subfamily: antennal insertions concealed under “shelf” (and therefore not visible from above), and hypomeron of prothorax with well-developed post-coxal process. It is placed in Pinophilini based on an elongated procoxae (as long as the profemora), broad, oval, fully exposed trochantin, and a conspicuous second abdominal segment. It is placed in Pinophilina, rather than Procirrina, based on the presence of well-preserved pair of paratergites on segments III-VIII. Characters which distinguishes this new species from other Pinophilina include the lack of an emarginate shape of the rear margins of the elytra (Herman 2010), broad neck and having two pairs of paratergites on each side of segments III-VI.
Afrinophilina orapa species nov. (Figs 2, 3, 4 and 7).
Etymology: The epithet of the new species is a name of the deposit where the specimen was discovered, which in itself is derived from Sesarwa (a San or Bushmen language), and is named after a nearby cattle post, meaning ‘the resting place of lions’ (De Beers Group website https://www.debeersgroup.com/about-us/our-operations/our-mines/botswana).
Material studied: Holotype, adult (specimen number BP./2/27586a (part) and BP./2/27596 (counterpart), Herbarium, Evolutionary Studies Institute (ESI), University of the Witwatersrand, Johannesburg, South Africa).
Type locality and horizon: Botswana, Orapa Diamond Mine, lacustrine deposit, Upper Cretaceous (Davis 1977; and Haggerty et al. 1983).
Diagnosis: As for the genus Afrinophilinagen. nov. .
Description: Body slender measuring 8.81 mm in length (from tip of mandibles to tip of abdomen) and 1.82 mm in width (from exterior edge of one elytron to edge of another elytron, at widest point). Covered with setae of variable length throughout (Figs. 2, 3, 4 and 7).
Head (Fig. 5), 1.44 mm long (from tip of mandible to anterior margin of pronotum) and 1.01 mm wide at widest point just anterior to neck, making it approximately 1.4 x longer than wide, with distinct curved temples; width of head 1.4 x broader than width of neck constriction, with broad neck. Eyes (Fig. 5) not well preserved, circular to slightly oval, located closer to base of antennae, covering 1/3 of temple. Antennae filiform (Figs. 2 and 3), approximately length of head and prothorax, bases hidden under “shelf” at base of head; proximal antennomers incomplete, but antennomere 1 appears less or equal length as antennomers 2 and 3, antennomeres 9 and 10 funnel shaped, antennomere 11 poorly preserved, but with funnel shape, suggesting that it had spiniform pencil of setae, in general antennae with setae visible in many places. Mandibles curved, sickle-shaped, left mandible curved over right, possibly with traces of teeth posteriorly. Pair of long setae posterior to base of mandibles. Labial palps, represented only by indistinct segment or portion of segment adjacent to left mandible. Labrum poorly preserved. Several indistinct structures in region which could be interpreted as spines or lobes. Margin between labrum and frontoclypeus apparently straight, curved at corners. Gular sutures fully separate, apparently reaching posterior margin of head.
Pronotum (Fig. 2, 3 and 4) rectangular with curved sides, longer than wide (0.59 mm wide, 0.68 mm long); length 0.9 x less than that of head, width 1.1 x broader than head, anterior margin forms slight collar around the neck, posterior margin gently curved. Superior marginal line apparently deflexed, reaching from anterior margin of prothorax and tapering off just before posterior corner of prothorax. Distinct post-coxal process of hypomeron visible. Longitudinal carina of furcasternum present, sharp, apparently extending anterior towards longitudinal carina of basisternum, crossed by transverse basisternum carina anteriorly.
Elytra (Figs. 2, 3 and 4) jointly 1.6 x wider and 1.1 x longer than pronotum. Elytra oval, collectively wider than long (each 1.61 mm long, from posterior margin of pronotum to anterior margin of elytron, 1.76 mm wide); with epipleural margin, but no obvious epipleural ridge; separated at base by small scutellum, with faint striae. Elytral posterior margins curved evenly, non-emarginate, apparently with long setae.
Prothoracic legs (Figs. 2, 3 and 4) with broad coxa, long as femur, trochanter large and oval, tibia narrow at base, becoming broader distally, lacking any distinct medial expansion, with row of setae in posterior mid-section, possibly representing longitudinally arranged protibial combs (Fig. 6), distal surface with grooves which also represent ctenidium, only tarsomere 1 preserved, moderately expanded, triangular, with curved distal surface fringed with short setae. Mesocoxae indistinct, remainder of leg represented by poorly preserved fragments of femur and tibia, femur covered with long setae, remnants of tarsal segments visible. Thorns on mesotibia not visible. Metathoracic coxae apparently large and extended, trochanter difficult to discern, femurs projecting beyond side of body, tibia 1 ½ x long as femur, with tibial thorn at apex, tarsomere 1 about 1 ½ x longer than tarsomere 2, approximately same for tarsomere 5, although with poorly-preserved distal segments.
Abdomen (Fig. 2, 3 and 4) approximately 3 x elytral length and 1.2 x elytral width, 3 ½ x as long as wide (4.96 mm long, 1.56 mm wide), apparently with waist (but this may be due to poor preservation of first visible segment), tapering strongly from segment VI. Segments II-VIII visible, segment II distinct, without paratergites, with intercoxal carina in the middle that extends into segment III, segments III-VIII each with pair of paratergites, segments III-VI each with two pairs of paratergites, segment IX with pair of setiferous latero-apical processes, separated by pair of pointed structures interpreted as tergal plates (Naomi 1989).
Palaeoenvironment: There has been no recent review of the Pinophilina. Apparently, most of them prefer wet tropical forest environments (Campbell and Peck 1989), a view shared with the Procirrina (Herman 2010). Extant paederines are commonly found in damp places, under logs, litter or foliage, while some have been recorded inhabiting caves and ant nests.
Remarks: The maxillary palps crucial for differentiating the tribes within the Paederinae are not preserved. Its first protarsal segment (protibial combs) is dilated with a setiferous margin as for the Pinophilini. However, there are other taxa, for example,Scymbalium and Micrillis (classified as Lathrobiiniincertae sedis ), with similar features (Bogri et al. 2020). The tribe Lathrobiini was ruled out based on an invisible, typical small and unmodified apical (fourth) maxillary palpomere. Interestingly, this species shares the characters of having an elongated procoxae and well-developed abdominal segment II with Mesostaphylinus(Solodovnikov et al. 2013), but is more similar to the Pinophilina in other features. The elongated procoxae are not typical forMesostaphylinus . The abdominal segment II is not usually preserved in fossils, as it is mostly hidden behind the elytra, making it difficult to compare this character.