Stephenbrooksia multifurcata Willmann, 1993

Makarkin, Vladimir N. & Perkovsky, Evgeny E., 2024, Nothochrysinae (Neuroptera: Chrysopidae) from the early Eocene Fur Formation, Denmark, with description of a new genus, Zootaxa 5433 (4), pp. 529-545 : 530-534

Stephenbrooksia multifurcata Willmann, 1993

( Figs 1–3 )

Stephenbrooksia multifurcata Willmann, 1993: 241 , 244, Figs 2 , 3 ; Nel et al., 2005: 67; Makarkin & Archibald, 2013: 143, Fig. 2.1 ; Archibald & Makarkin, 2015: 360 (Table 1).

Type material. Holotype NHMD-624881A & DK 307A (original number GM 2000.4) (part), deposited in the NHMD; NHMD-624881B & DK 307B (original number GM 2000.4) (counterpart), currently deposited in the NHMD; collected by Henrik Madsen. Overlapped fore- and hind wings (basal parts absent in the counterpart).

Additional material. FUM-16651, collected by Ole Burholt, and deposited in the FM. A strongly crumped incomplete specimen.

Type locality and horizon. Denmark: northern Jutland (Region Nordjylland): Mors Island ( Morsø Kommune ): Ejerslev. The precise collecting locality of FUM-16651 is unknown. Earliest Eocene ( Fur Formation ) .

Re-description. Holotype (based on the part and counterpart). Forewing 14.0 mm long, 5.2 mm wide. Costal space broad proximally, narrow distally. Most subcostal veinlets simple (five middle veinlets shallowly forked in distal half), relatively densely spaced proximally, very dense distally. Sc well discernible distally, relatively long. RA and its veinlets indiscernible distally, ending on margin before wing apex. Subcostal space narrow; basal subcostal crossvein located slightly proximad origin of RP. RA space moderately broad, with 14 crossveins: basal crossveins with apices slightly inclined to wing base; most distal crossveins with their apices strongly obliquely to wing apex. RP originating close to wing base (at 0.15 length). Anterior trace of RP zigzagged, apically not forked; with 14 pectinate branches, all (except one distal-most) forked, mostly three to four times. Basal crossvein between RP, M (1r-m) long, connecting anterior trace of RP, MA in proximal part of im length. M dividing to MA, MP markedly distad origin of RP. MA probably forked distad Psc; both branches shallowly forked. MP probably deeply forked at Psc; both branches simple. im long, narrow (length/width ratio 6.3:1). Crossvein between MA, MP (1im) rather short. Psm poorly developed, zigzagged. Crossvein 2m-cu connecting im and CuA located nearly in middle of im. CuA probably with three branches (one forked); continuing into well developed, only slightly zigzagged Psc, which continues into outer gradate series of crossveins. CuP pectinately forked with two long branches; its anterior trace shallowly forked. 1icu located near origin of CuP; 2icu connecting CuA and anterior trace of CuP (distad origin of distal branch of CuP). 1c: 2c length ratio 0.26:1. A1 deeply forked. A2 incomplete. A3 not preserved. Two gradate series of crossveins; inner series arranged in strongly broken line, with 13 crossveins distad MA; outer series arranged in smooth line, with 11 crossveins distad RP2 .

Hind wing 10.2 mm long (as preserved; estimated complete length ca. 11.5 mm), 4.2 mm wide. Costal space narrow; preserved subcostal veinlets simple, very densely spaced in distal part. Sc indiscernible distally. Subcostal space narrow; crossveins not detected. RA long, indiscernible distally, ending on margin before wing apex. RA veinlets indiscernible. RA space moderately narrow basally, broadening distad; with 11 crossveins inclined obliquely to wing base in proximal half, strongly obliquely to apex in distal half. Anterior trace of RP zigzagged, apically forked; with 11 pectinate branches; RP 1- RP 7 forked, mostly three times; other branches probably simple. MA basally (slightly proximad origin of RP) dividing into two branches, not fused with RP (connecting by long crossvein 1r-m). MA 1 forked at Psc; both branches forked again; MA 2 forked distad Psc (alternatively: MA 2 forked slightly proximad 1im, then its anterior branch fused with MA 1 for long distance). Psm poorly developed, strongly zigzagged. MP fused with CuA for very short distance; forked distally at Psc, both branched forked again distad Psc. Proximal crossvein between MA, MP (1im) very long. CuA pectinate, with three simple branches. Psc poorly developed, strongly zigzagged. CuP, anal veins not preserved. Two gradate series of crossveins: inner series arranged in strongly broken line, with 11 crossveins distad MA; outer series arranged in smooth line, with 9 crossveins distad MA.

Specimen FUM-16651. Forewing ca. 11.6 mm long (as preserved; estimated complete length ca. 12.5–13 mm), 4.7 mm wide. Costal space broad proximally, narrow distally. Most subcostal veinlets in proximal half simple (two veinlets forked in left wing), relatively densely spaced; in distal half, veinlets very densely spaced, eight of these forked in right wing, up to five in left wing. Sc relatively long; its distal part not preserved. RA and its veinlets poorly discernible distally, ending on margin before wing apex. Subcostal space narrow; basal subcostal crossvein located slightly distad origin of RP. RA space moderately broad, with 15 crossveins (left wing): proximal crossveins perpendicular to RA; most distal crossveins with their apices strongly oblique to wing apex. Anterior trace of RP zigzagged, apically not forked; with 16 pectinate branches (left wing), all (except one distal) forked, mostly three to four times. Basal crossvein between RP, M (1r-m) long, connecting anterior trace of RP, MA in proximal part of im length. M dividing to MA, MP markedly distad origin of RP. MA probably forked distad Psc; one branch shallowly forked. MP probably deeply forked at Psc; both branches forked. im long, narrow (length/ width ratio 4.4:1). Crossvein between MA, MP (1im) rather short. Psm poorly developed, zigzagged; its proximalmost crossvein (between RP 1, MA) ends in distal part of im. Crossvein 2m-cu connected im, CuA located nearly in middle of im. CuA probably with two branches (two forked in right wing); continuing into well developed, only slightly zigzagged Psc, which continues into outer gradate series of crossveins. CuP pectinately forked with two long simple branches. 1icu located near origin of CuP; 2icu connecting CuA and anterior trace of CuP (distad origin of distal branch of CuP). 1c: 2c length ratio 0.2:1. A1, A2 shallowly forked. Two gradate series of crossveins; inner series arranged in strongly broken line, with 14 crossveins distad MA; outer series arranged in more smooth line, with ten preserved crossveins distad RP 2.

Hind wing 10.3 mm long (as preserved; estimated complete length ca. 11 mm), ca. 4.2 mm wide. Costal space narrow; preserved subcostal veinlets simple (one forked), widely spaced in proximal part. Sc, RA poorly discernible distally. Subcostal space very narrow; crossveins not detected. RA space relatively narrow in proximal part, with five preserved crossveins (basal crossveins with apices inclined to wing base). RP with six preserved branches. MA, MP poorly preserved basally (it is unknown if MA fused with RP or not). MA distally poorly preserved; probably forked at Psc (one branch forked again distad Psc). MP not fused with CuA (connected by short crossvein), forked at Psc. Psm poorly developed, strongly zigzagged. Proximal crossvein between MA, MP (1im) long. CuA pectinate, with three branches. Psc poorly developed, strongly zigzagged. CuP, anal veins not preserved. Two gradate series of crossveins, both incomplete.

Remarks. The configuration of the hind wing MA in the holotype of S. multifurcata is strongly aberrant. It is deeply forked proximad the origin of RP, but is not forked before its distal branching in any other Chrysopidae , including specimen FUM-16651.

Figures

FIGURE 1. Stephenbrooksia multifurcata Willmann, 1993, holotype. A, part (NHMD-624881A); B, counterpart (NHMD- 624881B). Scale bars = 2 mm.

FIGURE 2. Stephenbrooksia multifurcata Willmann, 1993, wing venation of the holotype based on the part and counterpart.A, forewing; B, hind wing. Scale bar = 2 mm (both to same scale).

FIGURE 3. Stephenbrooksia multifurcata Willmann, 1993, specimen FUM-16651. A, specimen as preserved; B, venation of right forewing; C, venation of basal part left forewing; D, venation of basal part left hind wing (C, D converted to standard view, with apex to the right). Scale bars = 2 mm (C, D to same scale).