Clinops svachai, 2020

Batelka, Jan, Perkovsky, Evgeny E. & Prokop, Jakub, 2020, Diversity of Eocene Ripiphoridae with descriptions of the first species of Pelecotominae and larva of Ripidiinae (Coleoptera), Zoological Journal of the Linnean Society 188, pp. 412-433 : 414-416

CLINOPS SVACHAI BATELKA & PROKOP , SP. NOV.

( FIGS 1A–E, 2, 3A, 3B)

Holotype: Female No. PřFUK003 preserved in a transparent piece (18.88 × 20.10 × 4.70 mm) of Baltic Eocene amber from Lithuania. One syninclusion of a fragmentary dipteran, no other syninclusions except for microscopic fragments of plants, air bubbles and thin flattened fractures are present.

Description: Body black, elongate, total body length as preserved 5.67 mm; elytra length 4.99 mm. Integument with irregular, shallow, rough, wider than deep, densely arranged punctures. The whole body, including all the appendages, covered with short setae, sloping backwards, setae much denser on elytra ( Figs 1A, 2). Completely preserved specimen except for tarsomeres of left hind leg.

Head ( Figs 1B, 2): Subglobular, 1.5× longer than wide, occiput does not overlap pronotal disc; integument sparsely covered by fine short setae. Antennae with 11 antennomeres; scape (antennomere I) elongate, cylindrical, as long as antennomeres II + III combined; pedicel (antennomere II) globular, third of the length of antennomere I; antennomere III cylindrical, 2× longer than antennomere II; antennomeres IV–X with short, finger-like projections about 2.5× longer than the width of the base of their respective antennomeres; antennomere XI with finger-like projection without discernible base, similar in length to those on antennomeres IV–X. Antennal sockets in front of eye incision, separated from eye by smooth cuticle with two thin convergent notches. Maxillary palpomeres four-segmented, cylindrical, ultimate palpomere slightly curved, as long as preceding two palpomeres combined. Lacinia spatulate, densely covered with long thin microtrichia. Labial palpi simple, only ultimate palpomere well visible. Mandibles short, with smooth external edge, light in colour. Labrum and labium distinct, both rectangular in shape. Compound oval eyes reach posterior ventral edge of head, frontally incised in their upper half, eye-width in narrowest part about 12 facets.

Prothorax: Pronotal disc weakly convex in posterior half, covered with dense, minute, semi-erect setae; distal corners blunt, shallowly rounded; median lobe only slightly indicated, lateral carina absent. Prosternum triangular in lateral view. Procoxa small; profemur narrow; protibia long and slender, without tibial spurs, with apical edge terminating in a dense row of regular, thin, spiniform setae ( Figs 1A, 1B, 2); pretarsus about 1.2× as long as protibia, tarsomeres long and slender, at least the two basal tarsomeres with edges bearing spiniform setae similar to those on tibia; pretarsal claws long, bidentate (long terminal tooth with another slightly shorter inner tooth close to the first one).

Mesothorax: Mesoscutellar shield indiscernible. Mesepisternum narrow, rounded at ventral edge, with the pointed edge reaching elytral base. Mesepimeron as wide as mesepisternum, with both distal edges straight, parallel. Mesocoxa small, almost narrow along anterior edge of metaventrite. Mesofemur slightly tapering apically; mesotibia without tibial spurs, as long as mesotarsus ( Fig. 1C); tarsomeres and pretarsal claws similar to those on front leg ( Figs 1D, 2, 3A).

Metathorax: Metepimeron narrow, almost hidden below elytron, posteriorly prolonged above metacoxa. Metanepisternum tapering posteriorly, with rounded distal edge, about 3× wider at the edge adjacent to the mesepimeron. Metaventrite of trapezoidal shape in profile, as long as metanepisternum. Metacoxa elliptical in lateral view, proximally bordered by shallow sulcus along ventral third of metasternal edge ( Figs 1A, 2); metafemur much widened, flattened laterally on its inner side, metatibia with two distinct tibial spurs ( Figs 1E, 3B), otherwise similar to pro- and mesotibia; metatarsus longer than metatibia, metatarsomeres and pretarsal claws similar to those on front and midlegs.

Elytra elongate, slightly convex, as long as abdomen, with rounded apex, without shoulders and ridges, well sclerotized, with dense punctuation and short setae, with epipleuron reaching almost half the length of ventrite IV. Hind wings almost entirely covered by elytra, visible folded apices with dark membrane, non-transparent.

Abdomen with five ventrites, of which ventrite III is shortest and ventrite V about 1.5 ×as long as ventrite III.

Differential diagnosis: Pelecotominae genera are currently based mainly on the tibial spur formula (hereinafter TSF) in combination with other unique characters in individual genera (e.g. shortened elytra, modified maxillary palpomeres, pectinate pretarsal claws, etc.). Despite an obvious tendency since the Mesozoic for pelecotomines to have fewer tibial spurs (with the exception of extant New Zealand genera), and the apparent relationships between both South American genera and also among all three New Zealand genera, no valid phylogenetic hypothesis is available for the generic relationship within the subfamily ( Engel et al., 2019). The description of the female fits the current definition of the genus Clinops , because of its identical TSF (currently unique within the subfamily), bidentate pretarsal claws, unmodified terminal maxillary palpomere and similar body shape. The genus tentatively only includes three South African extant species based on one male and two female holotypes ( Engel et al., 2019). Clinops svachai can be distinguished from its extant congeners by more convex pronotal disc (disc almost flattened in female C. inexpectatus ; Engel et al., 2019), by rounded occiput (occiput strongly elevated above pronotal disc in C. inexpectatus , and slightly elevated in male of C. perpessus Engel, Falin, Batelka, 2019 ), and by much longer elytra (5.3×) in comparison with length of pronotal disc in female of C. badius Gerstaecker, 1855