Samlandotoma seidlitzi Alekseev, 2019

Samlandotoma seidlitzi Alekseev, 2019

( Figs 5–6 View FIGURE 5 View FIGURE 6 )

Material examined. One specimen with collection number JDC-13732 [ JDC], adult, male. Complete beetle inclusion with partially exposed metathoracic wings and apical portion of aedeagus is included in transparent amber piece with dimensions 40 × 26 × 3 mm. Syninclusions are represented by three specimens of Nematocera ( Diptera ), few stellate Fagaceae trichomes.

Strata. Baltic amber, most probable from the Eocene amber-bearing layers of Blaue Erde (Blue Earth) within the Prussian Formation; estimated age: middle-late Eocene ( Bukejs et al. 2019).

Locality. Yantarny village (formerly Palmnicken), Sambian (Samland) Peninsula, Kaliningrad Region, western Russia.

Note. Body length of beetle JDC-13732 (including visible part of head) 4.8 mm, maximum body width 1.3 mm. Although the specimen is partially obscured on the ventral side and the dorsal view is partially hidden by crack in amber matrix, no morphological differences were found, and the specimen is assigned to extinct Samlandotoma seidlitzi Alekseev, 2019 . All tibiae of JDC-13732 with paired pubescent apical spurs of equal length (tibial spur formula 1-1-2 of Samlandotoma is mistakenly reported in the original description), posterior pronotal angles triangular (“obtuse, rounded” is mistakenly reported for the holotype in the original description).

Taxonomic assignment. Characters of Samlandotoma that preclude its original misplacement within Pelecotominae or Ripiphoridae have been discussed by Batelka (2021). The inclusion shows the combination of characters corresponding to adults of the subfamily Scraptiinae within Scraptiidae , namely: (1) body form elongate-oval with base of pronotum narrower than anterior elytral margin; (2) eyes emarginate anteriorly; (3) head constricted posteriorly; (4) antennal insertions exposed from above; (5) antennae 11-segmented, non-clubbed; (6) temples present; (7) pronotum laterally margined in basal one-half of its lenght; (8) pronotum and elytra without transverse strigae; (9) procoxae subcontiguous, projecting well below prosternum; (10) protrochantins exposed; (11) elytra irregularly punctate, without transverse strigae; (12) tibiae slender, all tibial and tarsal segments lacking crenulation; (13) tibial spurs paired, equal in length, well-developed, pubescent; (14) tarsi 5-5-4 with all penultimate tarsomeres lobed; (15) tarsal claws simple; and (16) abdomen with five ventrites and ventrite 1 not much longer than ventrite 2. Interfacetal setae in compound eyes are absent, posterior pair of pits or depressions in pronotum apparently not discernible.

The genus Samlandotoma shares the unique, within Scraptiidae , pectinate antennae with males of the monotypic North American genus Pectotoma Hatch , placed in the scraptiid tribe Allopodini by Young (1976) and with males of the monotypic Tasmanian Xylophilostenus Lea, 1917 , placed in Scraptiidae by Lawrence (1987). The antennae of Samlandotoma consists of simple scape and pedicel (non-pectinate, conical in form), pectinate antennomeres 3–9, antennomeres 10 elongately triangular and antennomere 11 simple, spindle-shaped, whereas the antennomeres 3–10 of Pectotoma male and 4–10 of Xylophilostenus male are pectinate. Additionally, base of each projection on antennomeres 3–9 is located at distal margin of each antennomere in Samlandotoma in contrast to location of projection near the base of antennomere in Pectotoma .

Samlandotoma seidlitzi Alekseev, 2019 has lobed metatarsomere 3 and therefore is placed within the extant tribe Scraptiini View in CoL .