Acerataspis? revelata (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

Acerataspis? revelata (Brues, 1910) comb. nov.

Fig. 5

* Pimpla revelata Brues, 1910

Material.

Photographs examined of the holotype (#PALE-2158, referred to as #h) and of another specimen (#PALE-2159), which Brues (1910) placed tentatively in the same species, but expressing doubts; obtained from the MCZ.

Stratum.

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

Description.

Sex unknown in holotype, second specimen is a female; we support the notion that the two specimens belong to the same species and base our description on both of them. Holotype showing ventral aspect; specimen #PALE-2159 in lateral (head and mesosoma) and dorsolateral (metasoma) aspect. Holotype with part of head, base of antennae, mesosoma, fore and most of hind wings, partial hind leg and segments on to partial five of metasoma. Specimen #PALE-2159 with head, almost complete antennae, mesosoma, fore wings, hind legs including tarsi and complete metasoma. Body length 9 mm (#PALE-2159).

Fragments of dark colouration on most of body including T1, T2-T5 with orange or reddish colouration and lighter hind margins.

Head with face apparently protruding (#PALE-2159), eyes smaller than usual in ichneumonids. Antennae with scape short and ovoid (#h), with more than 30 mostly transverse flagellomeres (#PALE-2159). Mesosoma rather short, with rather high and short pronotum with strong epomia; mesopleuron with strong but probably interrupted epicnemial carina curving anteriorly at mid height of pronotum (#PALE-2159), complete ventrally and dipping into medial sternal groove (#h); at least mesosternum, mesopleuron and metapleuron covered in strong and very dense punctures (#h). Propodeum with pleural carina complete (#PALE-2159), remaining carination unclear but probably with some portion of apical transverse and lateral longitudinal carina present (#PALE-2159); metapleuron rather high, with several diagonal carinulae starting at lower hind corner of metapleuron (visible in both specimens, in #h on both sides from ventral). Fore wing 6.4 mm (#PALE-2159 5.0 mm), with areolet oblique-quadrate and strongly petiolate; pterostigma 4.5 × longer than wide; cell 2R1 of average proportions (3 ×); vein 2m-cu with strong curve and one wide bulla anteriorly; 1cu-a meeting M + Cu far distally of 1M; 3Cu a bit longer than 2cu-a; 1M distinctly curved at base. Hind wing with cell 1Cu rather narrow and with subparallel sides; vein 1Rs a bit longer than rs-m; 1Cu about 1.5 times longer than cu-a. Hind legs with femur short and thick (#p 2.7 ×); hind tibia (#p 4.5 ×) with strong spines on outer side, mostly lightly coloured with dark base and apex (#PALE-2159). Metasoma rather short and stout; T1-T3 with two subparallel dorsal carinae; last tergites and last sternite enlarged; short ovipositor indicated, probably not much longer than metasoma height at apex (#PALE-2159).

Interpretation.

Brues (1910) interpreted the holotype as showing a dorsal aspect, which probably led him to miss some crucial characters. The stout body, protruding face, short flagellomeres, and carinae on T1-T3 place these fossils in the subfamily Metopiinae . The extant genus Acerataspis seems a good match in terms of tergite carination, carinulae low on metapleuron and closed areolet, but the latter is much larger in the extant species and the antenna much more elongate; we thus place it in this genus with a question mark.

Metopiinae Förster, 1869

Hypsicera ? Latereille, 1829

Figures

Figure 5. Acerataspis? revelata (Brues, 1910), comb. nov. A. Photograph of the holotype obtained from the MCZ; B. Our interpretative drawing of the holotype; C. Photograph of the paratype obtained from the MCZ; D. Our interpretative drawing of the paratype. Thicker lines indicate outlines of body structures, thinner lines show characters inside these outlines, and dotted lines represent uncertain interpretations.