Malthinus (Malthinus) karenpankowskiae, PANKOWSKI & Fanti, 2023

PANKOWSKI, MAXIMILIAN G. & Fanti, FABRIZIO FANTI, 2023, Six new species of fossil soldier beetles (Coleoptera: Cantharidae) from Eocene Baltic amber, Palaeoentomology 6 (3), pp. 300-312 : 304-306

Malthinus (Malthinus) karenpankowskiae sp. nov.

( Figs 3 , 4 )

Holotype. Female , inclusion in Baltic amber, housed at the Smithsonian National Museum of Natural History, USNM PAL 787825 .

Syninclusions: A few small debris.

Etymology. Species named in honor of Karen Pankowski, the fearless, caring mother of the first author.

Diagnosis. The globular and distally pointed last maxillary palpomere, the short elytra, head restricted behind the eyes, and the elytra with impressed punctuation clearly place this taxon in the genus Malthinus .

Only three fossil species of Malthinus have been described previously to this paper, all from Baltic amber ( Kuśka & Kania, 2010; Fanti & Damgaard, 2018; Pankowski & Fanti, 2022). The new species described here is easily distinguished from these other Malthinus species by its strongly transverse pronotum with no expansion posteriorly or narrowing anteriorly.

Locality and horizon. Amber mine in the Yantarny settlement, Sambian Peninsula, Kaliningrad region, Russia. Middle Eocene (Lutetian) (47.8–41.2 Ma) to late Eocene (Priabonian) (37.8–33.9 Ma).

Description. Female, defined on the basis of wide and rounded last sternite. Body length: about 5.0 mm. Body entirely dark brown without yellow spots on elytra.

Adult, alate, slender. Head completely exposed, strongly narrowed behind eyes, very wrinkled, with deep punctation, interocular dorsal distance about 3.5 times greater than eye diameter. Eyes convex, sub-elliptical, located in upper lateral part of the head. Mandibles falciform, elongate, thin. Maxillary palpi 4-segmented, with last palpomere globular-elongate and apically pointed. Labial palpi 3-segmented, with last palpomere globular and apically pointed. Antennae filiform, 11-segmented, short, reaching about half of the elytra; antennomere I elongate, slightly club-shaped; antennomere II about 2.1 times shorter than antennomere I; antennomere III slightly shorter and sturdier than antennomere II; antennomere IV longer than previous one; antennomeres V–X subequal, slightly shorter than previous one; antennomere XI elongate, very slightly pointed; all antennomeres covered by short setae. Pronotum strongly transverse, slightly wider than head, equipped with short setae and sparse punctation, anterior and posterior margins straight and bordered (anterior margin strongly bordered), sides straight, anterior corners slightly acute, posterior corners rounded. Scutellum triangular shaped, pointed apically. Elytra short, revealing four abdominal segments uncovered, wider than pronotum, covered with deep punctation in rows and short setae, parallel-sided, not dehiscent, rounded at apex. Hind wings slightly infuscate, exceeding elytra and not reaching last abdominal segment. Metasternum with slightly rounded posterior margin, covered with dispersed and short setae and very shallow punctation. Sternites transverse, wide, with shallow punctation and short pubescence. Last tergite and last sternite wide, small and rounded. Legs slender, pubescent; coxae elongate, stout; trochanters elongate with rounded apex; femora enlarged, rather straight; tibiae cylindrical and thin, equipped with apical spurs, pro- and mesotibiae shorter than pro- and mesofemora, metatibiae longer than metafemora. Tarsomere I thin, elongate; tarsomere II about 2.0 times shorter than tarsomere I; tarsomere III short; tarsomere IV strongly bilobed; tarsomere V elongate, slightly curved, slender; claws simple without tooth. Male unknown.

Remarks. The yellow squared amber piece measures approximately 9 × 9 × 8 mm. The inclusion is slightly bent but complete; the head and antennae are folded and some parts of the beetle are covered with white emulsion.

Figures

FIGURE 3. Malthinus (Malthinus) karenpankowskiae sp. nov. in Baltic amber. Holotype (USNM PAL 787825). A, Dorsal view. B, Detail of head and pronotum. C, Lateral view. D, Ventral view. Scale bars = 0.5 mm.

FIGURE 4. Malthinus (Malthinus) karenpankowskiae sp. nov. in Baltic amber. Holotype (USNM PAL 787825). A, Detail of head and pronotum. B, Detail of head and metasternum. Scale bars = 0.3 mm.