Mesypochrysa nielseni, Makarkin & Perkovsky, 2023

Makarkin, Vladimir N. & Perkovsky, Evgeny E., 2023, New Limaiinae (Neuroptera: Chrysopidae) from the early Eocene Fur Formation, Denmark, including an unexpected finding of a Mesozoic genus, Zootaxa 5383 (1), pp. 57-66 : 58-59

Mesypochrysa nielseni sp. nov.

Figs 1–3

Etymology. From the surname of Christian Nielsen, collector of this fossil, who donated it to the Natural History Museum of Denmark (NHMD).

Type material. Holotype: MGUH 34285 (accession number GM 2023.55; Christian Nielsen collection No. 330), deposited in the NHMD. A nearly complete, partly crumpled and damaged forewing.

Type locality and horizon. Denmark: Mors Island : Ejerslev (56.926720°N, 8.909836°E), collected by Christian Nielsen in September 2013. Early Eocene (Fur Formation: Silstrup Member: ash-layers +25 to +30) .

Diagnosis. RA entering margin slightly before wing apex; A1, A2 simple.

Description. Forewing 14.5 mm long, 5.1 mm wide (length to width ratio 2.84). Costal space moderately broad, widest at level of basal crossvein 1sc-ra. All preserved subcostal veinlets simple, rather widely spaced. Sc relatively short, slightly curved towards RA apically, but apex indiscernible. Subcostal space narrow; basal subcostal crossvein (1sc-ra) located at level of origin of RP; distal crossveins not preserved. RA long, entering margin slightly before wing apex; six short, closely-spaced veinlets apically. RA space broad, with 17 crossveins. RP originating relatively close to wing base (at 20% complete length). Anterior trace of RP zigzagged, apically shallowly forked; with 13 pectinate branches, all forked once except distal-most (i.e., RP13 simple). Basal crossvein between RP, M (1r-m) almost not preserved (only very short part near RP), probably short, connecting anterior trace of RP, MA within im at proximal one-eighths of its length. M dividing to MA, MP slightly distad origin of RP. Both MA, MP probably deeply forked at Psc. im long, tapering basally (length/width ratio ca. 4:1). Crossvein between MA, MP (1im) long. Psm very poorly preserved. Crossvein 2m-cu connected im, CuA at nearly distal end of im (slightly proximad 1im). CuA probably with two simple branches. CuA continuing into well developed, only slightly zigzagged Psc, which continues into outer gradate series of crossveins. Two gradate series of crossveins slightly convergent; inner series with 11 preserved crossveins distad MA (12 when complete); outer series with 12 crossveins distad RP2. CuP deeply forked; its anterior branch shallowly forked. 1icu located far from origin of CuP; 2icu connecting CuA, anterior branch of CuP. c1: c2 length ratio 0.62: 1. One very short crossvein (1cu-a1) connects CuA, A1. A1, A2 simple. Crossvein between A1, A2 (1a1-a2) long, located proximad 1cu-a1; crossvein between A2, A3 (1a2-a3) fragmentarily discernible, located proximad 1a1-a2. Jugal lobe well developed; its margin very stout; presumed jugal vein stout.

Remarks. The limaiine affinity of Mesypochrysa nielseni sp. nov. is undoubted. All diagnostic character states of the subfamily (see Nel et al. 2005; Makarkin & Archibald 2013) are present in this species, including the short Sc; the long RA terminating near the wing apex bearing dense simple veinlets; the elongate intramedian cell tapering basally; and the far distal location of the crossvein between the intramedian cell and CuA.

We consider the forked anterior branch of CuP in the holotype to be an anomaly, as CuP is forked once in another (undescribed) specimen of the presumably same species as in other species of the genus .

The jugal lobe with the presumed jugal vein is folded ( Fig. 2A ).

The area of the termination of Sc is preserved, crumpled distally, but the apical part of Sc and its veinlets are very poorly discernible ( Fig. 2B ). However, setae are well discernible, suggesting that veinlets located well distad the apparent apex of Sc belong to RA ( Fig. 2B , ra); more proximal setae suggest that Sc may theoretically end on the costal margin ( Fig. 2B , sc), but these setae may also belong to inclined veinlets of RA.

Figures

FIGURE 1. Mesypochrysa nielseni sp. nov., holotype MGUH 34285 (ex. Christian Nielsen collection No. 330). A, part; B, counterpart. Scale bar = 2 mm (both to same scale).

FIGURE 2. Mesypochrysa nielseni sp. nov., holotype MGUH 34285 (ex. Christian Nielsen collection No. 330), details of the forewing. A, basal part showing the folded jugal lobe; B, region of apical part of Sc; C, same, counterpart; D, apical part of wing, counterpart (C, D converted to standard view, with apex to the right).All wetted with ethanol. ra, rows of setae suggesting presence of veinlets of RA; sc, rows of setae suggesting possible termination of Sc at the costal margin. Scale bars = 1 mm (A), 0.5 mm (B, C, D).

FIGURE 3. Forewing venation of Mesypochrysa nielseni sp. nov., holotype MGUH 34285 (ex. Christian Nielsen collection No. 330). Scale bar = 2 mm.