Intertorular area with prominence that can be a carina or tooth-shaped (also referred to as inner antennal process (iap)). Fore wing disc bare or with setae reduced to setal bases (pilose only in Pteropilosa gen. n.), with marginal fringe, fore wing always with thickened juncture between marginal vein and submarginal vein (parastigma), marginal vein elongate, postmarginal and stigmal vein shortened, postmarginal vein usually shorter than stigmal vein. Mesonotum with complete notauli. Hind tibia with two spurs.

This key is modified after Krogmann (2013) and includes the two new fossil genera described herein.

Figure 2. 

Tenuicornus dominicus gen. et sp. n., showing general habitus and diagnostic characters. A General habitus in frontolateral view, showing rather long exerted part of the ovipositor B Head and mesosoma in dorsal view, mesosoma with polished mesonotum, foveolate notauli, and absent frenal line C Head in frontolateral view, with deep facial impression and enlarged setae at each side of lateral margin of the impression D Head and antennae in frontolateral view, at slightly different angle than C, with nail-shaped inner antennal process (iap) visible and highlighted with a red line; antennae inserted at ventral margin of eyes, with long scape, and 6-segmented, clavate funicle E Fore wing without a tuft of erect setae at parastigma (pst) and without pilosity or setal bases on wing disc. Scale: 500 µm (A); 200 µm (B–D).

Pteropilosa lailarabanorum sp. n.

Female holotype, preserved in Eocene Baltic amber (56-34 Ma). Holotype deposited in the amber collection of the State Museum of Natural History, SMNS collection number BB-2815.

Funicle of female 6-segmented with funicular segments 3-6 distinctly transverse, i.e., shorter than wide (Fig. 1D); toruli positioned near upper margin of eyes (upper third of eyes); intertorular prominence tooth-shaped, positioned slightly below level of toruli; shape of head almost round (Fig. 1D). Fore wing pilose (Fig. 1B); marginal vein less than four times as long as stigmal vein; parastigma without a tuft of erect setae (Fig. 1B). Mesosoma sculptured and irregularly imbricate with short and transverse strigulate lines; frenal line present (Fig. 1C).

The generic name Pteropilosa is composed of two parts. The first being Ptero-, which is derived from the old-Greek “pteryx”, meaning “wing”; the last letters -pilosa are derived from the Latin “capillosus”, meaning “hairy”. It can be roughly translated as “hairy wings”, referring to the most striking unique feature of this new genus. The generic name is feminine in gender.

See genus.

Female: total body length 1.62 mm; length of head 0.32 mm, of mesosoma 0.64 mm, of metasoma 0.86 mm. Body without metallic luster. Head: height 0.35 mm. Shape of head round (globose) and head smooth, without sculpture; no depression on face; mandibles small (not measurable). Eyes rather big and slightly egg-shaped, 0.22 mm high and 0.19 mm wide. Intertorular prominence tooth-shaped and positioned between toruli, but slightly below level of toruli. Antennae: inserted well above ventral margin of eyes (in upper third of eyes); scape length 96 µm, pedicel length 48 µm, pedicel rather short and stout; funicle 6-segmented. First funicular segment wider than long, F2 longer than wide. F3-F6 wider than long, distally broadened club-like (F1: length: 33 µm × width: 37 µm; F2: 40 µm × 38 µm; F3: 47 µm × 56 µm; F4: 48 µm × 69 µm; F5: 48 µm × 71 µm; F6: 54 µm × 77 µm); all funicle segments with sensilla. Clava egg-shaped, 0.14 mm long and 81 µm wide. Wings: fore wing disc pilose, without fuscous band. Elongate admarginal setae absent. Fore wing length 1.19 mm and width 0.33 mm; submarginal vein 0.42 mm long, marginal vein 0.33 mm and postmarginal vein 76 µm long, stigmal vein curved, 76 µm long; stigma slightly thickened and uncus visible. Hind wing length 0.98 mm and width 0.23 mm, only two hamuli visible. Legs: length of hind tibia 0.24 mm, hind femur 0.35 mm, hind trochanter 46 µm, hind coxa 0.15 mm. The other legs cannot be measured due to the position of the specimen within the amber. Mesosoma: pronotum, mesoscutum and mesoscutellum completely reticulated. Frenal line clearly visible and foveolate; frenum 0.55 times as long as mesoscutellum. Length of pronotum 0.25 mm, of mesoscutum 0.13 mm, of mesoscutellum 50 µm, of frenum 29 µm. Axillae large, medially connected. Metanotum with distinct foveae; lateral panel of metanotum wide and smooth. Metascutellum thin; not reaching anterior margin of metanotum. Propodeum coarsely reticulated. Metasoma: petiole (Mt₁) small, transverse, hardly recognizable. Metasomal tergites Mt₂ to Mt₉ smooth, Mt₂: 0.23 mm, Mt₃: 42 µm, Mt₄: 0.15 mm, Mt₅: 0.13 mm, Mt₆: 67 µm, Mt₇ 0.10 mm, Mt_8/9: 70 µm. Ovipositor 0.12 mm (top view) exerted beyond end of gaster.

Following the latest available identification key of Krogmann (2013), Pteropilosa lailarabanorum would be determined as Sciatherellus. However, there are distinct differences between the two genera. In addition to the pilose fore wings which are unique in Pteropilosa (Fig. 1B), Sciatherellus differs from P. lailarabanorum in having six antennal funiculars that broaden distally, with F3-6 distinctly transverse (Fig. 1D). In contrast, no funicular segment in Sciatherellus is wider than long. The fore wings of Sciatherellus also possess two prominent dark transverse bands that are absent in Pteropilosa, and the stigmal vein is straight in contrast to that of P. lailarabanorum, which is distinctly curved (Fig. 1B). The main differences between Pteropilosa and Neocalosoter are the pilose wings, the sculptured mesosoma, and the position of the toruli. In Pteropilosa, the antennae are inserted distinctly above the lower margin of the eyes, at around 2/3 of the height of the eyes (Fig. 1D). In the description of Neocalosoter (by Girault and Dodd in Girault 1915), it is stated that the antennae in this genus are “inserted at mouth border”, i.e., below the lower margin of the eyes. However, the position of the toruli in P. lailarabanorum is not unique within Cerocephalinae. Sciatherellus, Dominocephala, Muesebeckisia, and Gnathophorisca also have the antennae inserted above the lower margin of the eyes. Muesebeckisia and Gnathophorisca are easily distinguishable from Pteropilosa by their enlarged and conspicuously thickened mandibles. Furthermore, Muesebeckisia and Gnathophorisca share a fuscous band on the fore wing, which is absent in P. lailarabanorum. The recently described fossil genus Dominocephala can be distinguished from P. lailarabanorum by the elongate mandibles and the set of multiple setae on the lower facial process, both of which are not found in P. lailarabanorum. Dominocephala also features a fuscous band on the fore wing not present in P. lailarabanorum.

Named after Laila and Raban Ohlhoff, the grandchildren of the private donor.

Tenuicornus dominicus sp. n.

Female holotype, preserved in Lower Miocene Dominican amber (20-15 Ma). Holotype deposited in the amber collection of the Senckenberg Forschungsinstitut und Naturmuseum Frankfurt am Main, Germany, collection number SMF Be 2395.

Funicle of female 6-segmented and clavate with F1–F2 longer than wide and F3–F6 wider than long and distally broadening; scape elongate (1/3 of total antennal length) (Fig. 2D). Face deeply impressed with one distinct seta at each side of lateral margin of the impression anterior to mandibular articulation; seta long and thickened, slightly clavate in shape (Fig. 2C). Inner antennal process (iap) very thin and nail-like, located above level of toruli at upper margin of facial impression. Position of iap distinctly above ventral margin of eyes, on level with middle of eyes (Fig. 2C, D). Fore wing without a tuft of erect setae at parastigma. Wing disc bare, without setal bases. Marginal vein four times as long as stigmal vein (Fig. 2E). Prepectus large and triangular. Mesonotum almost completely polished (Fig. 2B). Exerted part of ovipositor long, approximately 1/4 of gaster length (Fig. 2A).

The first letters of the generic name Tenui- are derived from the Latin word “tenuis”, meaning “thin” or “sharp”. The last letters -cornus of the generic name are derived from the Latin word “cornus”, meaning “horn”. The generic name is male in gender and refers to the thin inner antennal process.

See genus.

Female: total body length 2.07 mm; length of mesosoma 0.92 mm, of metasoma 1.02 mm. Body without metallic luster. Head: height 0.39 mm, width 0.38 mm. Face deeply impressed. Shape of head cuboid; mandibles not visible, hidden in facial depression. Margin of facial depression with rough surface and with a thickened seta on each side (length of setae 85 µm). Inner antennal process (iap) positioned distinctly above level of toruli; nail-like, 0.11 mm long, with basis wider than apex, orientated anteroventrally. Eyes large and egg-shaped, 0.25 mm high and 0.2 mm wide. Antennae: inserted at ventral margin of eyes; scape long and slightly curved, length 0.25 mm; pedicel length 75 µm, rather short and stout; funicle 6-segmented with first two funicular segments longer than wide (F1: length: 71 µm × width: 52 µm; F2: 68 µm × 60 µm) and F3-F6 wider than long, distinctly broadening distally, club-like (F3: 59 µm × 72 µm; F4: 60 µm × 74 µm; F5: 58 µm × 80 µm; F6: 52 µm × 86 µm). Clava egg-shaped: 97 µm long and 77 µm wide. Wings: fore wing long and slender (length 1.53 mm and width 0.55 mm); submarginal vein 0.57 mm long, marginal vein 0.38 mm long, postmarginal vein 0.11 mm long, stigmal vein 99 µm long; stigma slightly thickened and uncus visible. Wing disc bare, setal bases absent. Elongate admarginal setae present. Hind wing length 1.27 mm and width 0.27 mm, three hamuli present. Mesosoma: pronotum and anterior part of mesoscutum with slight traces of strigulate surface sculpture; mesonotum otherwise polished. Notauli foveolate. Length of pronotum 0.37 mm, length of mesoscutum 0.22 mm, length of mesoscutellum 0.22 mm; no frenal line. Axillae medially connected. Mesopleuron (in lateral view) height 0.29 mm, width 0.36 mm. Prepectus enlarged and triangular in shape (0.14 mm × 0.17 mm). Length of metanotum 39 µm; length of propodeum 72 µm. Propodeum without a median carina or plicae. Legs: coxae strong and stout. Femora and tibiae long and slender (Fe₁: 0.45 mm; Fe₂: 0.32 mm; Fe₃: 0.41 mm; Ti₁: 0.39 mm; Ti₂: 0.49 mm; Ti₃: 0.42 mm). Metasoma: petiole (Mt₁) short and transverse, hardly visible. Metasomal tergites Mt₂ to Mt₉ smooth, Mt₂: 0.28 mm, Mt₃: 0.17 mm, Mt₄: 0.15 mm, Mt₅: 0.16 mm, Mt₆: 0.11 mm, Mt₇ 60 µm, Mt_8/9: 71 µm. Ovipositor 0.23 mm (top view) exerted beyond end of gaster.

The two genera that are most similar to Tenuicornus are Neocalosoter and Cerocephala. Tenuicornus runs to Neocalosoter in the key of Krogmann (2013) but differs from this genus in various features: Tenuicornus possesses a head that is deeply impressed (convex in Neocalosoter), the dark transverse bands on its fore wing are absent, and the propodeum has no traces of a median carina or plicae (Fig. 2B). The tentative similarity between Tenuicornus and Cerocephala is based on the deeply impressed face. However, Tenuicornus differs from Cerocephala by the absence of a tuft of setae on the parastigma on the fore wings (Fig. 2E), one of the most distinct characters for the generic classification of Cerocephalinae. Tenuicornus further differs from Cerocephala by the shape and position of the inner antennal process. In Tenuicornus, the process is shaped like a nail and positioned above the level of the toruli at the upper margin of the facial depression (Fig. 2C). In Cerocephala, the process is broader and stouter and positioned at or slightly below the level of the toruli. Furthermore, Cerocephala is described to have all funicular segments longer than wide (Westwood 1832), while in Tenuicornus only the first two funicular segments are longer than wide. The funicular segments three to six are wider than long (Fig. 2D).

The name dominicus is derived from the amber deposit in which the fossil was found.