Megaraphidia antiquissima, 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 : 44-46

Megaraphidia antiquissima sp. nov.

Figs 1 , 2 , 10A, B

Type material. Holotype RBCM P1555 , collected by John Leahy, unknown date, deposited in the RBCM collections. A nearly complete female specimen preserved in dorsal aspect.

Type locality and horizon. Hoodoo Face beds, McAbee, British Columbia, Canada; early Eocene (Ypresian) .

Etymology. From the Latin antiquissimus [-a, -um], oldest, most ancient, as this is the oldest record of the genus.

Diagnosis. May be distinguished from other species of Megaraphidia by head broad, not cuneate [clearly cuneate, i.e, narrowed posteriorly in M. ootsa ]; ovipositor relatively short (0.28 body length) [0.34 in M. ootsa ], relatively narrow costal space in forewing (2.3 times wider than subcostal space) [broader in M. exhumata (2.6), M. klondika (2.9), M. klondika (2.9), M. elegans (3.0); narrower in M. hopkinsi , M. ootsa (2.0)]; basal doi shorter than distal in hind wing [both approximately equal in length M. klondika ].

Description. Female. Body length (without ovipositor) approximately 15 mm. Head broad, apparently not cuneate (incompletely preserved). Prothorax probably relatively long (poorly preserved), approximately 3.0– 3.5 mm long (0.20–0.23 body length). Ovipositor relatively short, approximately 4.2 mm long. Details of body, legs not discernible by preservation.

Forewing approximately 12 mm long, approximately 3.5 mm wide (length/width: 3.43). Costal space broad, widest at proximal 1/5 of length; seven simple subcostal veinlets (right forewing: preserved, probably nine to ten total), all relatively closely spaced. ScP relatively long, terminating on costal margin opposite crossvein 2ra-rp; length from termination of ScP to pterostigma approximately equal to length of pterostigma. Subcostal space moderately broad, with basal crossvein located in middle between origin of RP, divergence of M, CuA; distal crossvein 2scp-r (forming basal margin of pterostigma) straight, slightly inclined toward base (i.e., joins C slightly proximad joining RA). Pterostigma relatively short, rather strongly pigmented. Three RA branches: one incorporated in pterostigma medially well discernible; second forming distal margin of pterostigma; third distad pterostigma; none forked. RA entering margin about halfway between pterostigma, apex. RA space with two crossveins forming two radial cells: 2ra-rp long, located well proximad pterostigma, opposite termination of ScP; 3ra-rp long, joins distal part of pterostigma along RA. RP originates in proximal part of wing (approximately 0.39 wing length), with four (right wing) or six (left wing) pectinate branches: RP1 deeply forked; its anterior branch simple, posterior branch forked once (both wings). RP3 deeply forked (right wing), and RP4 shallowly forked (right wing); other branches simple. One long intraradial crossvein rp1-rp2 between stem of RP, RP1. Three crossveins between RP, MA: 1r-m, 2r-m connecting stem of RP, MA; 3r-m connecting RP1, anterior branch of MA. M fused with CuA for short distance; forked well proximad origin of RP. MA deeply dichotomously forked twice. MP zigzagged, with three simple branches. Two intramedian crossveins form two doi, basal cell somewhat shorter than apical. Anterior trace of CuA strongly zigzagged, simple, fused with MP for short distance forming part of posterior margin of basal doi; posterior trace of CuA simple. CuP probably simple (distal portion not visible). Crossvein icu between CuA, CuP long. Crossvein cu-aa between CuP, AA1 closer to origin of CuA than to icu. Only basal AA1 discernible, AA2, AA3 not.

Hind wing approximately 11 mm long, approximately 3.05 mm wide (length/width: 3.61). Costal space moderately broad; four to five simple subcostal veinlets preserved, rather closely spaced. ScP relatively long; length from termination of ScP to pterostigma approximately equal to its length. In subcostal space, one crossvein detected (2scp-r, forming basal margin of pterostigma), straight, distinctly inclined toward base. Pterostigma elongate, slightly longer than in forewing. RA with three branches: first, within pterostigma, easily visible; second, forming distal margin of pterostigma, straight, oblique to margin; third, simple. RA terminating on margin about mid-way between pterostigma, apex. Three crossveins between RA, RP: 1ra-rp slightly distad 2r-m; 2ra-rp approximately opposite termination of ScP; 3ra-rp located in distal half of pterostigma along RA. RP originating at approximately 0.36 wing length. Anterior trace of RP simple apically, with four (left wing) to five (right wing) branches, in both wings one proximad 3ra-rp, three to four at beginning or distad 3ra-rp. RP1 deeply forked, its anterior branch simple, posterior forked once; RP2, RP 3 in left wing forked; other branches simple. One intraradial crossvein (rp1-rp2), between stem of RP, RP1. Three crossveins between R, M: 1r-m long, running subparallel to R; 2r-m connects stem of RP, MA; 3r-m connecting RP1, anterior branch of MA. M forked approximately at level of origin of RP. MA deeply dichotomously forked twice. MP pectinately branched, with probably three branches (right wing: poorly preserved), four probably simple branches (left wing). Two intramedian crossveins form two doi; basal doi markedly shorter than distal; one indistinct crossvein distad 2im (this may be artefact). One crossvein 2m-cu between M, Cu detected, connecting MP, CuA. Anterior trace of CuA simple distally, with one simple (but incompletely preserved) branch. CuP or CuP+AA1 partially preserved; anal veins not preserved.

Figures

FIGURE 1. Megaraphidia antiquissima sp. nov., holotype RBCM P1555, specimen as preserved. Scale bar = 5 mm.

FIGURE 2. Wing venation of Megaraphidia antiquissima sp. nov., holotype RBCM P1555. A, right forewing, B, left forewing; C, right forewing; 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.