Tytthonyx (Tytthonyx) stadili, Fanti & Damgaard, 2019

Fanti, Fabrizio & Damgaard, Anders Leth, 2019, New soldier beetles (Cantharidae) from Baltic, Burmese and Dominican ambers of the Anders Damgaard amber collection, Baltic Journal of Coleopterology 19 (2), pp. 101-125 : 119-122

Tytthonyx (Tytthonyx) stadili sp. nov.

( Figs. 17 - 20 )

Holotype. Female, in Dominican amber, accession No. ALDC0529 /ALD. Do.Can. 1

Type locality. Dominican Republic: Cordillera Septentrional, La Cumbre or Los Brachos or Guazumal mining sites.

Type horizon. Late Early/Middle Miocene (20– 15 MY, probably close to 16 MY). La Toca Formation.

Differential diagnosis. Today, 14 species of Tytthonyx live in the Dominican Republic and 19 in Hispaniola: Haiti and/or Dominican Republic (Perez-Gelabert 2008), and only one fossil of soldier beetles was described for this amber deposit ( Poinar & Fanti 2016). Tytthonyx geiseri Poinar & Fanti, 2016 is easily distinguishable from the new species for the smaller size (about 3 mm instead of 6 mm of Tytthonyx stadili sp. nov.), for the head more triangular behind the eyes, the more square pronotum and less bordered at the margins and sides, and also for the different shape of the antennomeres ( Poinar & Fanti 2016; Fanti 2017). The new species is here tentatively placed to the nominotypical subgenus, for the antennae slightly serrate (serrate or filiform in the females), where they are serrate in the females of the subgenus Thinalmus Gorham, 1881 ( Ramsdale 2002; Poinar & Fanti 2016).

Description. Adult, alate, robust. Female on the basis of the last sternite. Head around the antennae and eyes black that sinuously extends posteriorly, and yellow on the palpi, mandibles and near the pronotum; antennae with eight black antennomeres and the last three yellow ones; pronotum and scutellum entirely yellow; elytra black; metathoracic wings slightly burnished; legs testaceous-yellowish (light brown); abdominal segments dark brown. Body length: 6.0 mm. Head roundish, slightly triangular behind the eyes, completely exposed, as wide as pronotum, without punctation, totally covered by small and several setae. Eyes perfectly rounded, prominent, inserted in the lateral (and in the middle of the sides) part of the head, inter-ocular dorsal distance about 1.8-1.9 times greater than eye diameter. Mandibles long, very robust and thin apically, with tooth near the apex. Maxillary palpi 4-segmented; pubescent; palpomeres unequal in length; first palpomere robust and short; second palpomere elongate, cylindrical and enlarged in the middle; third robust, enlarged in the middle, and intermediate in length between the first two; last palpomere globular and pointed. Labial palpi 3-segmented, pubescent, with the last palpomere globular and pointed. Antennae 11-segmented, feebly serrate, short, slightly surpassing the elytral apex, reaching about the middle of the body, antennal insertion in the upper part of the head and very far from the eyes; scape very stout, club-shaped; pedicel stout, very slightly shorter than scape; antennomeres III-IV filiform, subequal in lenght and as long as pedicel; antennomeres V-IX feebly serrate (the five article very feebly); antennomere X filiform, elongate, slightly enlarged apically, thinner than previous; antennomere XI filiform, elongate, thin, rounded at apex; all antennomeres pubescent. Pronotum strongly transverse, with the margins and sides strongly bordered (particularly the anterior margin and anterior corners), without punctation, covered by small setae, surface not completely flat and slightly undulated and with longitudinal and very narrow impressed line in the centre of pronotum. Scutellum wide at base and only vaguely triangular, with apex truncate and straight. Elytra robust, as wide as pronotum, very short, slightly surpassing the metasternum and reaching the first abdominal segments, strongly rounded at apex; surface very feebly rugouse without punctation, with short setae. Posterior wings long, almost reaching the last abdominal segments. Metasternum elongate, trapezoidal, pubescent in the middle; ventrites transverse with few setae at sides; last sternite shorter than tergite, with triangular tip in the center and with a urophysis at sides starting from the penultimate sternite; last tergite slightly concave apically. Legs short and rather robust, pubescent; coxae massive; trochanters short and robust, with apically a tip rounded at apex; femora short, robust, very slightly curved; tibiae cylindrical, protibiae as long as profemora, mesotibiae slightly longer than mesofemora, metatibiae particularly thin, longer than metafemora; tarsal formula 5-5-5; first tarsomere 1.9 times longer than second tarsomere which is short and robust; third tarsomere very short, almost globular; fourth bilobed; fifth thin and elongate; claws simple and minute.

Etymology. In honor of the owner and CEO of Thornico Group and chairman for the fashion brand Hummel, Christian Nicholas Stadil.

Syninclusions. Few debris.

Remarks. The amber piece was bought by a miner from La Cumbre and then after being polished and shaped it was used to make it a precious jewel. The amber piece is spherical-elongate and the size is 15 x 19.5 x 8 mm. The matrix has a unique and limpid transparency that allows an exceptional and surprising vision of inclusion, which is complete. In this specimen, even the original color is clearly visible.

Figures

Fig. 17. Tytthonyx stadili sp. nov.ALDC0529/ALD.Do.Can.1 in Dominican amber. Holotype, dorsal view, bar = 1.0 mm.

Fig. 18. Tytthonyx stadili sp. nov. ALDC0529/ALD.Do.Can.1 in Dominican amber.A: Holotype, lateral view, bar = 1.0 mm; B: Holotype, detail of head, pronotum (ventral view) and sternum, bar = 500 μm; C: Holotype, detail of head, antennae, pronotum and elytra, bar = 500 μm.

Fig. 19. Tytthonyx stadilisp. nov.ALDC0529/ALD.Do.Can.1 in Dominican amber.A: Holotype, detail of head, bar = 200 μm; B: Holotype, detail of head and pronotum, bar = 200 μm; C: Holotype, detail of pronotum and elytra, bar = 300 μm; D: Holotype, detail of metathoracic wings and last tergites, bar = 500μm.

Fig. 20. Tytthonyx stadili sp. nov.ALDC0529/ALD.Do.Can.1 in Dominican amber.A: Holotype, detail of metasternum and ventrites, bar = 500 μm; B: Holotype, detail of last abdominal segments (ventral view), bar = 500 μm; C: Holotype, detail of legs, bar = 200 μm.