Megaraphidia ootsa, Archibald & Makarkin, 2021

Archibald, S. Bruce & Makarkin, Vladimir N., 2021, Early Eocene snakeflies (Raphidioptera) of western North America from the Okanagan Highlands and Green River Formation, Zootaxa 4951 (1), pp. 41-79 : 46-48

Megaraphidia ootsa sp. nov.

Figs 3 , 4 , 10C, D

Type material. Holotype RBCM P1556 , found by unknown person on an unknown date, deposited in the RBCM collections. A complete female in lateral aspect with four overlapping wings.

Type locality and horizon. Driftwood Canyon Provincial Park , near Smithers, British Columbia, Canada; early Eocene (Ypresian) .

Etymology. From the Ootsa Lake Group shale within which the holotype is preserved (specific epithet is a noun).

Diagnosis. May be distinguished from other species of Megaraphidia by head clearly narrowed posteriorly (cuneate) [broad, not cuneate in M. hopkinsi , M. antiquissima ]; ovipositor relatively long (0.34 body length) [0.28 in M. antiquissima ]; two intraradial crossveins in both wings [one in other species].

Description. Female. Body length (without ovipositor) approximately 15 mm. Head blackish, clearly narrowed posteriorly; antennae with ≥38 flagellomeres. Prothorax blackish, narrow, relatively short, approximately 2.5 mm long (0.17 body length). Mesothorax, metathorax poorly preserved, blackish. Legs pale, covered with dense, rather short setae; third tarsomeres strongly bifurcate. Abdomen with blackish tergites, sternites; 8th, 9th tergites extend laterally for relative short distance; ectoproct relatively large. Ovipositor relatively long, approximately 5.1 mm (0.34 body length).

Forewing approximately 12 mm long, 3.5 mm wide (length/width: 3.43). Costal space relatively narrow (two times wider than subcostal space), widest at 1/5 length (basal-most portion obscured); eight preserved subcostal veinlets (probably ≥10), all simple, relatively closely spaced. ScP long, terminating on costal margin notably distad crossvein 2ra-rp; length from termination of ScP to pterostigma approximately half length of pterostigma (measured along C). Subcostal space broad, with basal crossvein 1scp-r slightly proximad fork of M; distal crossvein 2scp-r (basal margin of pterostigma) markedly incurved (joins C proximad basad joining RA). Pterostigma rhombic (distal margin oblique, angled opposite to basal), relatively short, strongly pigmented. Two RA branches detected (branch presumed within pterostigma not discernible): one forming distal margin of pterostigma; other distad this (simple in right wing, forked in left wing). Stem of RA simple in right wing, forked in left wing, entering margin well before wing apex. RA space with two crossveins forming two radial cells: 2ra-rp located well proximad termination of ScP; 3ra-rp located in distal part of pterostigma along RA (at approximately 2.45 wing length), with five pectinate branches: RP1 deeply forked, its anterior branch simple, posterior forked once; other branches once or twice forked. Two intraradial crossveins: rp1-rp 2 in right wing between RP2, RP1, in left wing between anterior trace of RP, RP1; other between RP2, RP3. Three crossveins between RP, MA: 1r-m, 2r-m connecting stem of RP, stem of MA; 3r-m connecting RP1, anterior branch of MA. M joined with CuA for short distance (seen on left wing, obscured on right wing); forked well proximad origin of RP. MA deeply dichotomously forked twice (one branch in each right and left wings further shallowly forked). MP zigzagged with four simple, pectinate branches. Two intramedian crossveins forming two doi; basal doi slightly shorter than distal. Basal parts of Cu not visible. Anterior trace of CuA strongly zigzagged, fused with MP for short distance (forming part of posterior side of basal doi), with two pectinate long simple branches (left wing) or one deeply forked branch (right wing). CuP simple. Crossvein icu between CuA, CuP long. AA1 rather deeply forked; small portion of AA2 visible.

Hind wing approximately 11 mm long, approximately 3.4 mm wide (length/width: 3.24). Costal space relatively broad (incompletely preserved); four preserved subcostal veinlets (right wing) simple, widely spaced. ScP long; length from termination of ScP to pterostigma shorter than length of pterostigma. One crossvein detected in subcostal space (2scp-r, forming basal margin of pterostigma), slightly incurved. Pterostigma nearly equal in length with that in forewing. RA with two to three branches detected (branch presumed within pterostigma not discernible), branch forming distal margin of pterostigma straight; one (right wing) to two (left wing) simple, slightly curved branches distad pterostigma. Three crossveins between RA, RP: 1ra-rp located slightly distad 2r-m; 2ra-rp located notably proximad termination of ScP (left wing, but only slightly proximad in right wing); 3ra-rp located in distal half of pterostigma along RA. RP originating at approximately 0.36 wing length. Anterior trace of RP forked apically, with four branches, two proximad 3ra-rp, two distad. RP1 deeply forked, its anterior branch simple, posterior forked once; most other branches rather deeply forked. Two intraradial crossveins: one connecting stem of RP, RP1; other between RP2, RP3. Three crossveins between R, M: 1r-m very long, subparallel to R (basal portion obscured); 2r-m connecting stems of RP, MA slightly proximad 1ra-rp; 3r-m connecting RP1, anterior branch of MA. M forked close to or slight basad level of origin of RP. MA deeply dichotomously forked twice. MP: anterior trace zigzagged, with four simple pectinate branches (basal-most branch in left wing forked). Two intramedian crossveins forming two doi; basal doi markedly shorter than distal. One crossvein (2m-cu) detected between M, Cu straight, proximad 1im. CuA with two (left wing) to three (right wing) simple branches. Small portions of CuP preserved.

Remarks. In this specimen, light areas of the head, thorax, and abdomen ( Fig. 3 ) surely do not represent colouration of the living insect, but were most likely caused by post-mortem damage.

Figures

FIGURE 3. Megaraphidia ootsa sp. nov., holotype RBCM P1556, specimen as preserved. Scale bars = 5 mm.

FIGURE 4. Wing venation of Megaraphidia ootsa sp. nov., holotype RBCM P1556. A, right forewing, B, left forewing; C, right hind wing; D, left hind wing. Scale bar = 3 mm (all to scale).

FIGURE 10. Pterostigmata of Megaraphidia. A, M. antiquissima sp. nov., right wings of the holotype RBCM P1555; B, M. antiquissima sp. nov., left wings of same specimen; C, M. ootsa sp. nov., right hind wing of the holotype RBCM P1556; D, M. ootsa sp. nov., left wings of same specimen; E, M. klondika sp. nov., holotype, an overlapping forewing and hind wing SR03-01-01; F, M. klondika sp. nov., specimen SR-16-004-001-1. RAf, RA of forewing; Rah, RA of hind wing. Scale bars = 0.5 mm.