Lithochrysa meyeri, Makarkin & Antell & Archibald, 2022

Makarkin, Vladimir N., Antell, Gwen S. & Archibald, S. Bruce, 2022, A revision of Chrysopidae (Neuroptera) from the late Eocene Florissant Formation Colorado, with description of new species, Zootaxa 5133 (3), pp. 301-345 : 322-323

Lithochrysa meyeri sp. nov.

Figs 15 , 16

Type material. Holotype FLFO 11717a, b (part, counterpart), collected by Florissant National Monument staff in 2014. A relatively poorly preserved nearly complete specimen with all four wings overlapped.

Type locality and horizon. USA: Colorado: Teller County: Florissant: Lower Shale unit of Evanoff 2001 (precise collecting locality unknown); Eocene , late Priabonian ; Florissant Formation .

Etymology. From the surname of Herbert W. Meyer, whose works have greatly increased knowledge of Florissant fossils and their environment.

Diagnosis. May be distinguished from other species of the genus by 12 branches of RP [other species: ≤ 10 branches]; more proximal location of 1r-m (ca. at level of 2m-cu) [ L. borealis , L. ferruginea : clearly distad 2m-cu]; cells between branches of CuA distinctly longer than wide [ L. wickhami : cells between these only slightly longer than wide]; the hind wing RP1 located distad first crossvein ra-rp [ L. concinnula : proximad].

Description. Body, legs very poorly preserved, details not discernable; only basal part of antennae preserved. Body ca. 12–13 mm long.

Forewing 16.3 mm long, 6.0 mm wide (length to width ratio 2.72). Costal space moderately broad, most dilated at level of origin of RP. All preserved subcostal veinlets simple, relatively close spaced in proximal part, dense distally. Pterostigma indistinct. Distal part of Sc not discernible. Subcostal space moderately narrow, appears distally broadened; subcostal crossveins not detected. RA ending on margin just proximad wing apex. RA space relatively narrow, with 12 preserved crossveins (in total, apparently 13; distal-most crossvein not preserved). RP originating at ca. 0.22 of complete wing length. Anterior trace of RP slightly zigzagged; with 12 branches, all forked except two distal-most. Basal crossvein between RP, M (1r-m) connects anterior trace of RP, MA within im at proximal onesixth of its length. M slightly curved inward before its fork; dividing to MA, MP slightly distad origin of RP. MA, MP zigzagged, each deeply forked at Psc. Im elongate, incompletely preserved. Psm poorly developed, zigzagged. Crossvein 2m-cu connecting im, CuA at nearly proximal one-thirds of im. CuA probably with two simple branches. Psm well developed, almost not zigzagged, continuing to outer gradate series of crossveins. CuP deeply forked, with branches rather widely spaced; c1: c2 length ratio 0.48: 1 in right wing; 2icu connecting CuA, anterior branch of CuP. A1 simple. A2 fragmentarily preserved. Two gradate series of crossveins, nearly parallel; inner series slightly sigmoid, with 11 crossveins distad MA; outer series with nine crossveins distad RP2.

Hind wing ca. 15 mm long, ca. 5 mm wide. Costal space poorly preserved; subcostal veinlets simple, rather widely spaced. Pterostigma indistinct. Sc fragmentarily preserved. Subcostal space narrow; subcostal crossveins not detected. Distal part of RA not preserved. RA space rather broad, with 11 preserved crossveins. Origin of RP, basal part of RP1 not preserved. Anterior trace of RP slightly zigzagged, with 10 branches, all forked except two distalmost. Psm poorly developed, zigzagged. M dividing to MA, MP. MA not preserved in middle part; basally crossvein-like, distally zigzagged, forked once distad Psc. MP nearly straight before Psc; deeply forked at Psc. Proximal crossvein between MA, MP (1im) long. CuA pectinate, with three simple branches. CuP fragmentarily preserved. Psc well developed, slightly zigzagged. Anal veins not preserved. Two gradate series of crossveins: inner series with nine preserved crossveins distad MA (actual number probably 10); outer series with 10 crossveins distad RP2.

Figures

FIGURE 15. Lithochrysa meyeri sp. nov., holotype FLFO 11717. A, part; B, counterpart. Scale bars = 3 mm.

FIGURE 16. Wing venation drawings of Lithochrysa meyeri sp. nov., holotype FLFO-11717. A, left forewing; B, right forewing; C, right hind wings; D, left hind wing. Scale bar = 3 mm (all to scale).