Okanopteryx fraseri 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 : 85-91

Okanopteryx fraseri Archibald & Cannings , new species

Figs. 49–52 .

Diagnosis. Separated from other Okanopteryx species by: abdomen longer, 29.5 mm from proximal end of abdominal segment 3 to distal end of segment 7 [ O. macabeensis : 20.0 mm]. We have compared the abdomen lengths using segments 3 to 7 only, as the O. fraseri abdomen is missing from the middle of segment 8 distally and the margins of the two proximal segments are difficult to interpret ( O. jeppesenorum only known from wings). Wings distinct from O. jeppesenorum , O. macabeensis by CuA–A space narrower, usually two cell rows at widest between levels of origins of IR1, RP2, sometimes a single column of three [ O. jeppesneorum : always four; O. macabeensis : always three].

Material. Holotype: GSC 141104, part, housed in the Geological Survey of Canada collections, and F-778, counterpart, in the Thompson Rivers University collections ( Fig. 49 ), collected at the McAbee Hoodoo Face beds, Geological Survey of Canada locality code V-016800, collected by John Fraser, unknown date; paratype 1: RBCM P1551 ( Fig. 50 ), collected at the McAbee Hoodoo Face beds by John Leahy, date unknown, in the Royal British Columbia Museum collections; paratype 2: F-1091 ( Fig. 51 ), collected at the McAbee Hoodoo Face beds, date and collector unknown, in the Thompson Rivers University collections; paratype 3: PB-4157 ( Fig. 51 ), collected at the McAbee Hoodoo Face beds, date and collector unknown, in the Thompson Rivers University collections; paratype 4: F-1045 ( Fig. 52 ), collected at the McAbee Hoodoo Face beds, date and collector unknown, in the Thompson Rivers University collections; paratype 5: RBCM P1552 ( Fig. 52 ), collected at the McAbee Hoodoo Face beds, John Leahy, date unknown, in the Royal British Columbia Museum collections.

Description. Holotype, GSC 141104, F-778 ( Fig. 49 ). A mostly complete specimen in dorsal aspect but with the bases of some of the legs possibly displaced to a lateral or dorsal position; one leg, at least, with part lying above the thorax. Abdomen distal to middle of segment 8 missing; two wings lacking the apical portions and only partially, mostly poorly, preserved, the other two wings fragmented; all legs mostly complete but poorly preserved. As in diagnosis and: Head ( Fig. 10 N , Table 1 ): in dorsal view, about 3.6 mm across eyes at widest point; approximate length from anterior edge of antefrons to posterior of occiput 1.8 mm; at level of hind ocelli distance between eyes 1.2 mm, width of eye about 1.1 mm, length 2.3 mm; eyes rather compressed laterally, with acute but rounded postero-lateral corners; protuberance of clypeus and labrum not evident. Thorax: pterothorax about 7.5 mm long, 3.8 mm wide in dorsal view, prothorax 1.3 mm long. Wing ( Fig. 43B ): CuA–A space two cells wide between level of origin of RP2, IR1. Legs. No spines or other setae visible; some coxae evident; metafemur 5.6 mm, metatibia 5.0 mm, twice as long as abdominal segment 2. Wing 1. Mid-portion well preserved. Abdomen: colouration pale dorsally, extrapolated total length about 45 mm; segment 2, 2.5 mm long; segment 3, 6.3 mm long x 1.3 mm wide.

Paratype 1, RBCM P1551, wing ( Fig. 50 ). Missing the apical quarter and parts proximal to the nodus. Maximum width 6.8 mm. Hyaline with broad dark fascia between level of nodus, level of terminus of CuA (presumably to half of wing distal to nodus, as in O. jeppesenorum ) . Pterostigma not preserved. Most crossveins in postnodal, postsubnodal spaces aligned in region preserved (proximal half of these spaces). RP1 – IR1 space becomes two cells wide three cells distal to origin of IR1. IR1: origin four cells distal to origin of RP2 ; two cells wide ten cells distal to origin. RP2 : origin three cells distal to origin of IR2; linear, rather straight (distal quarter missing). IR2 origin at subnodus; straight, linear but slight zigzag near end of preserved portion (small portion missing near end). RP3-4 : origin half way between anterior-distal corner of quadrangle, nodus; almost complete: straight, linear. MA linear proximally, slight zigzag beginning between levels of origins of RP2 , IR1, increasingly zigzagged to extreme apical to this. MP linear, rather straight from quadrangle to terminus. CuA slightly zigzagged from level of quadrangle, increasing from about level of origin of RP2 ; CuA–A space two cells wide at widest (between levels of origins of IR1, RP2 ) .

Paratype 2, F-1091, wing ( Fig. 51 ). As RBCM P1551, except: antenodal space preserved, no accessory crossveins. Width 6.6 mm. IR1: origin six cells distal to that of RP2 . CuA–A space two cells wide at widest except one column of three .

Paratype 3, PB-4157, wing ( Fig. 51 ). As RBCM P1551, except the following. Much of antenodal space preserved, no accessory crossveins. RP3-4 : origin two thirds distance between anterior-distal corner of quadrangle, nodus. IR1: origin two cells distal to origin of RP2 . RP1 –IR1 space two cells wide six cells distal to origin. RP2 : origin 3.5 cells distal to origin of IR2. CuA–A space two cells wide at widest except one column of three .

Paratype 4, F-1045, wing ( Fig. 52 ). As RBCM P1551, except: almost all antenodal space missing. Width 6.4 mm. RP1 –IR1 space goes to two cells wide six cells distal to origin of IR1. IR1: origin three cells distal to origin of RP2 . RP3-4 origin: quadrangle not preserved, but similar distance from nodus. MP missing near terminus. CuA slightly zigzagged from level of origin of RP3-4 , increasing from about level of origin of IR1; two cells wide at widest except one column of three .

Paratype 5, RBCM P1552, wing ( Fig. 52 ). Smallest portion, from about base of IR1 to RP1 –IR1 space becoming two cells wide. Width 6.8 mm. Darkly infuscate throughout. Preserved portion as for RBCM P1551, except: RP1 –IR1 space becomes two cells wide five cells distal to origin of IR1. IR1: origin three cells distal to origin of RP2 . RP2 : origin three cells distal to origin of IR2 by preservation, but probably four. MA becoming zigzagged about level of origin of IR1. CuA probably becoming zigzagged about level of origin of IR2, increasing distal to it. CuA–A space apparently two cells wide at widest, unsure by preservation if a third cell wide as in F- 1091, PB-4157, F-1045 .

Etymology. The specific epithet is a patronymic formed from the surname of John Fraser, the collector and donor of the holotype, recognising his contribution.

Range and age. McAbee, BC, Canada; mid-Ypresian.

Discussion. The abdomen of the holotype is much longer than that of O. macabeensis ; indeed, the specimen as a whole is likely about 1.7 times longer than O. macabeensis , confidently setting these two species apart (see diagnosis). Based on known variation in extant species, this size difference is unlikely to be the result of intraspecific variation or sexual dimorphism.

Although the wing of the holotype of O. fraseri is only partially preserved, its CuA–A space is only two cells wide at this level, with an occasional single column of three. By this, we associate wings which share the colouration and other venational character states with either O. fraseri or O. macabeensis based on the number of cells across the CuA–A space between the levels of IR1 and RP2: three in O. macabeensis and two (sometimes a single column of three) in O. fraseri .

The thorax of O. fraseri may be more robust than that of O. macabeensis , however, it might also be that they are preserved at slightly different angles.

Figures

FIGURE 10. Heads of Zygoptera (A, B) and comparative Anisoptera, Anisozygoptera, Tarsophlebiidae, Stenophlebiidae (C– H); and Cephalozygoptera (I–Q).A, Zygoptera, Heteropodagrion superbum Ris redrawn from Fig. 318 of Garrison et al. (2010); B, Zygoptera, Minagrion ribeiroi (Santos) redrawn from Fig. 1842 of Garrison et al. (2010); C, Anisoptera, Gomphidae, Cyanogomphus waltheri Selys redrawn from Fig. 383 of Garrison et al. (2006); D, Anisozygoptera, Epiophlebia laidlawi Tillyard redrawn from Fig. 2 of Büsse (2016); E, Anisoptera, Aeshnidae, Limnetron antarcticum Förster redrawn from Fig. 16 of Garrison et al. (2006); F, Stenophlebia sp. redrawn from Tillyard & Fraser 1940, Fig, 4C; G, Tarsophlebiidae, Tarsophlebia eximia Hagen redrawn from Fleck et al. (2004) Fig. 1C; H, photograph of Tarsophlebia eximia in MCZ collections; I, Sieblosia jucunda redrawn from Hagen (1858, Plate 24, Fig. 1); J, Cephalozygoptera incertae sedis SR 14-003-004; K, Phenacolestes parallelus UCM-4545; L, Okanopteryx macabeensis, GSC 141101; M, Okanagrion beardi paratype 1, RBCM P1546; N, Okanopteryx fraseri GSC 141104; O, Okanopteryx macabeensis F-790; P, Dysagrion fredericii redrawn from Scudder 1890, plate 6, Fig. 10; Q, Dysagrion fredericii redrawn from Scudder 1890, plate 6, Fig. 2. G and H, I, J to O to scales, all 5 mm; others, originals without scales.

FIGURE 43. Okanagrion incertae sedis. SR 94-05-30: A, photograph; B, drawing; SR 11-51-07: C, photograph; D, drawing; RBCM P1550: E, photograph of top wing in G; F, drawing of wing in E; G, all three wings. A–D to scale; E, F to scale; G to scale; all scales 5 mm.

FIGURE 49. Okanopteryx fraseri holotype, GSC 141104/F-778. A, photograph of entire specimen (part: GSC 141104); B, drawing of wing. Both to scale, 5 mm.

FIGURE 50. Okanopteryx fraseri paratype 1, RBCM P1551. A, photograph; B, drawing. Both to scale, 5 mm.

FIGURE 51. Okanopteryx fraseri paratype 3, PB-4157. A, photograph; B, drawing; paratype 2, F-1091: C, photograph; D, drawing.All to scale, 5 mm.

FIGURE 52. Okanopteryx fraseri paratype 5, RBCM P1552. A, photograph; B, drawing; paratype 4, F-1045: C, photograph; D, drawing. All to scale, 5 mm.