Hypsicera? solidata (Brues, 1910) Spasojevic & Broad & Klopfstein, 2022

Spasojevic, Tamara, Broad, Gavin R. & Klopfstein, Seraina, 2022, Revision of 18 ichneumonid fossil species (Hymenoptera, Ichneumonidae) highlights the need for open nomenclature in palaeontology, Fossil Record 25 (1), pp. 187-212 : 187

Hypsicera? solidata (Brues, 1910) comb. nov.

Fig. 6

* Camerotops solidatus Brues, 1910

Material.

Photographs of the holotype (part only, #PALE-2239) obtained from the MCZ.

Stratum.

Teller County, Florissant shales, Colorado, USA. Late Eocene (Chadronian), 37.2-33.9 Ma.

Description.

Female. Holotype in ventro-lateral view, with nearly complete antennae, outline of head, details of mesosoma, one fore wing, partial fore and mid and nearly complete hind legs, and metasoma with ovipositor sheaths. Body length 6.1 mm.

Black or dark brown on head, mesosoma and T1, dark brown on antennae, red on hind legs and T2 until end of metasoma, orange on fore and mid legs; wing venation very light.

Head with face bulging, eye rather small (if interpreted correctly). Antennae stout, with about 23 flagellomeres; scape about 1.1 × as long as wide; first flagellar segments subquadrate, following transverse. Mesosoma short and compact; pronotum with long epomia and parallel wrinkles; mesopleuron with epicnemial carina strong and reaching at least to half the height of the pronotum, probably more; with deep mesosternal scrobe and possibly indication of sternaulus (which could be an artefact), and with very closely spaced, parallel wrinkles on most of its surface. Metapleuron large, higher than wide; propodeum rather short, with pleural, lateral longitudinal, and a low-sitting posterior and probably also anterior transverse carina complete, delimiting areas; median longitudinal carina unclear. Fore wing 3.0 mm, with areolet probably open; 1cu-a meeting 2Cu at same position as 1M; cell 2R1 short (2.1 ×). Legs very stout, hind femur 2.5 × and hind tibia 3.7 × as long as wide. Metasoma short, with both strongly sclerotized tergites and at least partial sternites; T1 about 1.6 × longer than wide, expanding towards apex, with distinct longitudinal lines which probably represent the median dorsal and dorsolateral carinae; T2 and following transverse; T6 and T7 of about same length as previous ones. Ovipositor short, around 1 mm long, and around as long as hind tibia, internal portion longer than sheaths.

Interpretation.

The bulging face, long malar space, short flagellar segments and thickened legs indicate either Metopiinae or the Orthocentrus genus-group of Orthocentrinae . Brues ( Brues 1910) placed the specimen in the latter, but the short scape and the presence of a clear epomia and costula clearly point to the former. Brues also stated that the "abdomen flaked off in the specimen" and did not make a decision about the sex; we note that the ovipositor sheaths are clearly visible, even though its base is crossed by a hind leg. Within Metopiinae , the placement is more difficult, but Hypsicera and Exochus Gravenhorst, 1829 seem a good match given the similarity of the propodeal carination, bow in 1M of the fore wing and long T7. If we interpreted the head correctly, the small eyes and the bulging of the face closer to the antennal sockets correspond more to Hypsicera . However, the longer and stouter ovipositor sheaths indicate Exochus , while the fore wing venation is typical for Exochus and only rarely seen in Hypsicera . Thus, even though we place the fossil in Hypsicera , this placement should be seen as preliminary with Exochus as a valid alternative.

Orthocentrinae Förster, 1869

Orthocentrus Gravenhorst, 1829

Figures

Figure 6. Hypsicera? solidata (Brues, 1910) comb. nov. A. Photograph of the holotype obtained from the MCZ; B. Our interpretative drawing of the fossil. Thicker lines indicate outlines of body structures, thinner lines show characters inside these outlines, and dotted lines represent uncertain interpretations.