Okanagrion worleyae Archibald & Cannings, 2021

Archibald, Bruce, Cannings, Robert A., Erickson, Robert J., Bybee, Seth M. & Mathewes, Rolf W., 2021, The Cephalozygoptera, a new, extinct suborder of Odonata with new taxa from the early Eocene Okanagan Highlands, western North America, Zootaxa 4934 (1), pp. 1-133 : 70-75

Okanagrion worleyae Archibald & Cannings , new species

Figs. 39–41 .

Diagnosis. Wings separated from those of O. threadgillae , O. beardi , O. liquetoalatum , O. lochmum , O. hobani , by shape: posterior margin less deeply curved; further from O. threadgillae by shape, nodus to apex 3.0 times maximum width [ O. threadgillae : 2.5]; further from O. angustum by narrower wing, about 4.5 mm wide at levels of nodus [ O. angustum about 5.5 mm]; from O. dorrellae by MP linear near margin (but partially known by preservation) [ O. dorrellae : zigzagged]; from O. beardi , O. dorrellae by MP, CuA sub-parallel at terminus on posterior margin [ O. beardi : distinctly wider, O. dorrellae : widening, but less distinctly as CuA zigzagged distally ( O. angustum , not known); from O. angustum , O. beardi by IR2 origin between RP1-2, RP3-4 (clearly preserved in holotype, not clear by damage in paratype 2, region not preserved in paratype 1) [ O. angustum , O. beardi : origin on RP1-2]; from O. hobani by main veins less deeply curved near margin; from O. lochmum by cells less dense in apical portion of wing: RA–RP1 space two cells wide distal to four cells proximal to pterostigma [ O. lochmum : 7–8 cells proximal], RA–RP1 space three cells wide about one cell distal to pterostigma [ O. lochmum : at base of pterostigma], RA–RP1 space maximum four wide from about four cells distal to pterostigma [ O. lochmum : four, then five cells wide about distal corner of pterostigma].

Further separated by colouration (sex unknown): wing lightly, uniformly infuscate across all known portions as preserved (might appear almost hyaline by preservation).

Type material. Holotype: SR 99-14-02 ( Fig. 39 ), collected at Republic A0307 by Providence Worley, 23.viii.1998, housed in the Stonerose Interpretive Center collections; paratype 1: SR 16-006-001 ( Fig. 40 ), collected at Republic A0307 by Kattia Rojas, 9.x.2016, in the Stonerose Interpretive Center collections; paratype 2: SR 11-21-09 ( Fig. 41 ), collected at Republic B 4131 by Eric Blumhagen, 2.viii.2008, in the Stonerose Interpretive Center collections.

Description. Holotype, SR 99-14-02, wing ( Fig. 39 ). Missing portion proximal to nodus. Shape: narrow oval distal to nodus, mostly symmetrical from lateral mid-line, except apex slightly anterior to this. Length: nodus to apex: 22.7 mm, origin of RP2 to apex: 18.5 mm, nodus to base of pterostigma: 17.2 mm; width 7.8 mm. Lightly infuscate throughout. Pterostigma anterior, posterior margins oblique, 3.5 longer than wide, subtends seven cells, no oblique brace vein. 37 crossveins preserved in postnodal space (probably two not preserved), distal-most one hyperstigmal; those in postsubnodal spaces not aligned. Three cells wide distal to pterostigma in costal space. RA meets margin close to, posterior to apex, RA slightly curved forward near margin. RA–RP1 space narrows at margin. RP1–IR1 space goes to two cells wide nine cells distal to origin of IR1. IR1 origin eight cells distal to origin of RP2; IR1 two cells wide eight cells distal to origin. RP2: origin apparently (by preservation) seven cells distal to origin of IR2. IR2 origin at subnodus. No crossvein O. All major veins linear except proximal portion of IR1. CuA–A space four cells wide at widest.

Paratype 1, SR 17-006-001, wing ( Fig. 40 ). Apical portion, from about termination of MA on posterior margin to apex; diagonally to near nodus on anterior margin. As for holotype except: pterostigma subtends 4.5 cells; four cells wide distal to pterostigma in costal space; RA terminates a bit further posteriad .

Paratype 2, SR 11-21-09, wing ( Fig. 41 ). Preserved from about level of nodus, missing portion of posterior-apical region, partly indistinctly preserved.As in holotype, except: length: nodus to apex: about 22.7 mm, origin of RP2 to apex: 17.9 mm, nodus to base of pterostigma: about 17.2 mm. Pterostigma almost four longer than wide, subtends unknown number of cells. Crossveins in postnodal space partially preserved, appear as dense as in holotype, none hyperstigmal. RA not preserved at margin. RP1-2 –IR2, RP1 –IR1, IR1– RP2 , IR2– RP3-4 spaces partially preserved, IR1, RP2 origin distances appear similar to holotype. IR2 origin at subnodus. No crossvein O. All major veins linear except proximal portion of IR1. CuA–A space five cells wide at widest (but region poorly preserved) .

Etymology. The specific epithet is a patronymic formed from the surname of Providence Worley, the collector and donor of the holotype, recognising her contribution.

Range and age. Exposures B 4131 and A0307 of the Tom Thumb Tuff Member of the Klondike Mountain Formation at Republic, Washington, USA; late Ypresian .

Figures

FIGURE 39. Okanagrion worleyae holotype, SR 99-14-02: A, photograph; B, drawing. Both to scale, 5 mm.

FIGURE 40. Okanagrion worleyae paratype 1, SR 16-006-001. A, photograph; B, drawing. Both to scale, 5 mm.

FIGURE 41. Okanagrion worleyae paratype 2, SR 11-21-09. A, photograph; B, drawing. Both to scale, 5 mm.