Cacomorphocerus coleae, Fanti & Pankowski, 2019

Fanti, Fabrizio & Pankowski, Mary K., 2019, A new soldier beetle of the extinct tribe Cacomorphocerini Fanti & Kupryjanowicz, 2018, Zootaxa 4651 (3), pp. 589-595 : 590-592

Cacomorphocerus coleae FANTI & M. K. PANKOWSKI sp. nov.

( Figs. 1–4 )

Description. Adult winged, elongate, slender, entirely brown to dark brown. Female with last urite rounded and rather short antennae. Body length 6.7 mm; antennae approximately 3.7 mm.

Head prognathous, rounded and slightly convex behind eyes, rather elongated anteriorly, with shallow and thin punctation, slightly covered by pronotum. Eyes wide, rounded, convex, prominent, inserted in lateral part of head. Mandibles poorly visible. Maxillary palps four-segmented, equipped with setae, palpomere I short and robust, pal- pomere II elongate and cylindrical, palpomere III of intermediate length between first two palpomeres, palpomere IV securiform. Labial palps three-segmented with last palpomere elongate and securiform. Antennae 12-segmented, pubescent, not particularly long and reaching middle of elytra, filiform with medial antennomeres modified, insertion rather far to upper margin of eyes and close together; scape robust and club-shaped; pedicel short, approximate- ly 0.6 times as long as scape; antennomere III filiform, as long as scape; antennomere IV filiform, slightly shorter than antennomere III; antennomere V as long as antennomere IV, sturdier and enlarged; antennomere VI saucershaped with a concavity on the side; antennomere VII saucer-shaped, asymmetrical, with rounded and long lobes; antennomere VIII flat and wide with a small concavity on a side; antennomeres IX–XII filiform with antennomere XII longer and slightly rounded at apex. Relative length ratios of antennomeres 1–12 equal to 14:7:13:12:12:6:4: 11:12.12:12:14. Pronotum elongate, sub-quadrate, narrower than head, sparsely covered with shallow punctation, surface strongly concave in the middle, anterior margin straight and not bordered, posterior margin rounded, sides sinuous, posterior corners rounded and without denticles. Scutellar shield triangular. Elytra very long, surpassing the last abdominal segment, parallel-sided, slightly rugose and equipped with raised short setae, wider than pronotum and about as wide as head, apexes rounded. Hind wings slightly infuscate and slightly longer than elytra, almost completely covered by elytra. Metasternum gibbous, pubescent; ventrites transverse, robust, with setae. Last urite rounded both dorsal and ventral side. Legs slender and not particularly long, densely pubescent with short setae; coxae very large and robust; trochanters globular, short; femora slightly enlarged and slightly curved; tibiae subcy- lindrical, thin, with a long and very curved spur on the side near the apex, pro- and mesotibiae shorter than pro- and mesofemora, metatibiae longer than metafemora; tarsi 5-segmented; tarsomere 1 elongate and robust; protarsomere 2 about 1.5 times shorter than protarsomere 1, mesotarsomere 2 almost half the length of mesotarsomere 1; meta- tarsomere 2 approximately 1.7–1.8 times shorter than metatarsomere 1; tarsomere 3 shorter than tarsomere 2 and flat at sides; tarsomere 4 bilobed and very flat; tarsomere 5 slender; claws thin, pointed at apex and with a small and obtuse denticle basally.

Etymology. Named in honor of paleobiologist Dr. Selina Cole. A mentor to the second author, she generously shares her time and knowledge and inspires with her love of science.

Holotype. Female, adult specimen included in a yellow Baltic amber piece: Accession No. USNM PAL 706454 in the Smithsonian’s National Museum of Natural History ( USNM).

Type locality. Yantarny, Baltic Sea Coast, Sambian Peninsula, Kaliningrad Region, Russia.

Type strata. Baltic amber, Middle-Upper Eocene, Prussian Formation, also known as the “blue earth” formation.

Syninclusions. Many botanical remains, gas vesicles (air bubbles), Diptera (a Chironomidae male with a disar- ticulated leg, and another small indeterminable specimen), various unidentified insect parts.

Differential diagnosis. Cacomorphocerus coleae sp. nov. is characterized by 12 antennal articles that are little modified, with antennomere VI saucer-shaped and asymmetrical, antennomere V enlarged and antennomeres VII and VIII difform. With its central antennomeres little modified, C. coleae sp. nov., appears related to C. eocenicus Bukejs, Fanti & McKellar, 2019 . C. eocenicus , however, is distinguishable based on its smaller size (about 5.2 mm instead of 6.7 mm for C. coleae sp. nov.), the different shape of its modified antennomeres VI–VIII, and for antennomere V that is less dilated and shorter ( Bukejs et al. 2019). C. coleae sp. nov. is also similar to Sucinorhagonycha samsockorum Fanti & Pankowski, 2018 . However, S. samsockorum possesses claws without lobes or teeth (an important diagnostic character at the taxonomic level for the family Cantharidae ), as well as antennomeres IV–V that are slightly dentate and antennomeres III and VII that are very little modified ( Fanti & Pankowski 2018).

Remarks. The amber piece measures 32 x 23 x 6 mm and weighs 2.4 grams. The inclusion is complete and easily visible except for a white cotton-like cloud (emulsion), not particularly thick, localized in some ventral parts around the head, the side of the ventrites and the last urite.

Figures

FIGURE 1. Cacomorphocerus coleae sp. nov. in Baltic amber. Holotype, lateral view, scale bar = 1.0 mm.

FIGURE 2. Cacomorphocerus coleae sp. nov. in Baltic amber. A: Holotype, lateral view, scale bar = 1.0 mm. B: Holotype, dorso-lateral view, scale bar = 1.0 mm. C: Holotype, detail of legs, scale bar = 0.5 mm. D: Holotype, detail of legs, scale bar = 0.5 mm.

FIGURE 3. Cacomorphocerus coleae sp. nov. in Baltic amber. A: Holotype, detail of head, pronotum and left antenna, scale bar = 0.5 mm. B: Holotype, detail of metasternum and ventrites, scale bar = 0.5 mm. C: Holotype, detail of last ventrites, scale bar = 0.5 mm. D: Holotype, detail of last ventrites, scale bar = 0.5 mm.

FIGURE 4. Cacomorphocerus coleae sp. nov. in Baltic amber. Drawing of antenna by Mary Pankowski, scale bar = 0.5 mm.