Orthocentrus? mortuaria Brues, 1910

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

Orthocentrus? mortuaria Brues, 1910 comb. nov.

Fig. 8

* Polysphincta mortuaria Brues, 1910

Material.

Photographs of the holotype (part, #PALE-2134) obtained from the MCZ.

Stratum.

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

Description.

Female. Holotype in lateral view, with head and a few segments of antennae, mesosoma, fore wings, and metasoma with ovipositor, all rather poorly preserved; legs and hind wings missing. Body length 6.3 mm.

Head light brown, mesosoma black with light brown portions, metasoma mostly light brown on T1-T3, remainder dark brown (the light brown colouration could actually be a preservation artefact: it shows different sculpture and its texture is repeated on the rock outside the body).

Head with face bulging below antennal sockets, with eye very small, with very long malar space. Antennae more than 3.9 mm, incompletely preserved. Mesosoma rather short, poorly preserved, unclear if with epicnemial carina. Propodeum with pleural carina and lateral longitudinal carina, maybe also with posterior transverse carina. Fore wing 4.1 mm, rather short and stout, with areolet open and vein 2Rs longer than 3M; vein 1cu-a strongly inclivous meeting M + Cu clearly distally of 1M; cell 2R1 only 2.9 × longer than wide. Metasoma compressed from about fourth segment; T1 short and tapering towards base, with latero-median carinae converging on basal half, parallel on apical half; T2 and following tergites transverse. Ovipositor 0.5 mm.

Interpretation.

The bulging face with small eyes and long malar space are only found in Metopiinae and Orthocentrinae , and wing venation and ovipositor shape point to the latter. Given the size, 1cu-a meeting M + Cu clearly distally of 1M, and possible presence of the lateral portion of the epicnemial carina, Orthocentrus is the best guess, but the poor preservation of the fossil precludes a certain placement.

Phygadeuontinae Förster, 1869 (sensu Santos (2017)

Figures

Figure 8. Orthocentrus? mortuaria (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.