Okanagrion hobani 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 : 52-65

Okanagrion hobani Archibald & Cannings , new species

Figs. 24–35 .

Diagnosis. Wings separated from those of all other Okanagrion species by some or all main veins anterior to CuA more deeply curved near margin ( O. angustum not known); from O. lochmum by cells less dense in apical portion of the wing: see RA–RP1 space becomes two cells wide, three cells wide, four–five cells wide as it its diagnosis; from O. angustum , O. beardi by IR2 origin between RP1-2, RP3-4 [ O. angustum , O. beardi : origin on RP1-2]; 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. dorrellae by MP linear to margin [ O. dorrellae : zigzagged near margin]; from O. dorrellae , O. angustum , O. liquetoalatum by wing shape [ O. dorrellae , O. angustum : relative width measured two cells proximal to origin of RP2 perpendicular to apical margin, see their diagnoses; O. liquetoalatum : measured length (arculus to apex) / maximum width; others similar, see diagnosis of O. liquetoalatum ]; from O. liquetoalatum , O. dorrellae by wing shape: length (arculus to apex) / maximum width 3.2 [ O. liquetoalatum : 2.6; O. dorrellae 3.7; others similar to O. hobani ( O. lochmum , O. worleyae , O. angustum not comparable by preservation)]; from O. worleyae by shape: posterior margin more deeply curved.

Further separated by colouration (male, female unknown): proximal approx. 2/5 hyaline, dark apical to this except wide lighter fascia with mid-point just distal to mid-way between nodus, pterostigma, extending from anterior margin to or almost to posterior margin; size and extent of light fascia differs from: O. threadgillae about a third as wide, extending to mid-wing; O. dorrellae , lochmum , O. beardi : about half as wide or less, extending apparently to mid-wing ( O. dorrellae ) or close to posterior margin ( lochmum , O. beardi ); O. angustum apparently similar in portion preserved; O. liquetoalatum : hyaline throughout; O. worleyae : lightly infuscate throughout known wing.

Type and additional material. Holotype: F-1052 ( Fig. 24 ), McAbee, unknown collector and date, housed in the Thompson Rivers University collections . Paratype 1: SR 11-21-33 A, B ( Fig. 25 ), collected at Republic B 4131 by Suzie Brazee, 12.vi.2008, housed in the Stonerose collections ; Paratype 2: SR 02-24-14 A, B ( Fig. 26 ), collected at Republic B 4131 by Stonerose staff, 29.viii.2002, housed in the Stonerose collections: a well preserved disarticulated wing ; Paratype 3: SR 94-05-22 A, B ( Fig. 27 ), collected at Republic B 4131 by Shay Hoban 15.v.1994, housed in the Stonerose collections ; Paratype 4: SRUI 99-96-55 A, B ( Fig. 28 ), collected at Republic A0307 by Joanne West, 28.iv.2013, housed in the Stonerose collections ; Paratype 5: F-1140 ( Fig. 29 ), collected at McAbee, collector and date unknown, housed in the Thompson Rivers University collections ; Paratype 6: SR 00-04-05 ( Fig. 30 ), collected at Republic B 4131 by Janelle Bush, 1-x-2000, housed in the Stonerose collections ; Paratype 7: F-1044 ( Fig. 31 ) collected at McAbee, unknown collector and date, housed in the Thompson Rivers University collections ; Paratype 8: RBCM P1547 ( Fig. 32 ) collected at McAbee by John Leahy, date unknown, housed in the Royal British Columbia Museum collections ; Paratype 9: RBCM P1548 ( Fig. 32 ), collected at McAbee by John Leahy, date unknown date, housed in the Royal British Columbia Museum collections . Additional material: SR 95-03-30 ( Fig. 33 ) collected at Republic A0307 B by Dorothy Anthony 25.ix.1994, housed in the Stonerose Interpretive Center collections; SR 10-72-03 ( Fig. 33 ), collected Republic B 4131 by Heather Johns, 29.viii.2010, housed in the Stonerose Interpretive Center collections; SR 06-62-06 ( Fig. 30 ), collected at Republic B 4131 by Karl Volkman , 8.vi.2006, housed in the Stonerose Interpretive Center collections; SR 13-005-017 ( Fig. 28 ), collected at Republic B 4131 by Dustin Bellin , 3.vi.2011, housed in the Stonerose Interpretive Center collections; SR 17-006-001 ( Fig. 32 ), collected at Republic B 4131 by Toni Brender , 30.iv.2017, housed in the Stonerose Interpretive Center collections; SRUI 99- 71-07 ( Fig. 34 ), collected Republic B 4131 by Karl Volkman , 28.iv.2017, housed in the Stonerose Interpretive Center collections; RBCM P1549 ( Fig. 34 ), collected at McAbee by John Leahy , date unknown, housed in the Royal British Columbia Museum collections .

Description. Holotype,F-1052,forewing( Fig.24 ).Oval distal to nodus,symmetrical from lateral mid-line to apex. Length arculus to apex: 27.9 mm, nodus to apex: 22.2 mm, origin of RP2 to apex: 18.5 mm, arculus to base of pterostigma:22.0mm, nodus to base of pterostigma:16.0mm;maximum width 8.8mm.Colouration as in diagnosis.Pterostigma 3.5 times longer than wide; anterior, posterior margins oblique; subtends seven cells; no oblique brace vein.Crossveins preserved in postnodal, postsubnodal spaces not aligned. Costal space distal to pterostigma maximum (mostly) three cells wide in area preserved. RA meets margin near, posterior to apex; slightly upturned near margin. Wing dense with cells throughout, increasingly dense apically. RP2: origin 5.5 cells distal to origin of IR2. IR2: origin near, proximal to subnodus. RP3-4: origin about 2/3 from arculus to subnodus. Arculus very close to, immediately proximal to Ax2 (effectively same level). All major veins linear (proximal portion of IR1 not preserved). No crossvein O. CuA terminates on posterior margin at level of mid-point between nodus, pterostigma; CuA–A space five wide cells at widest.

Paratype 1, SR 11-21-33 A, B, hind wing ( Fig. 25 ). Portions proximal to nodus not preserved (arculus, quadrangle). As for holotype except: shape: anterior margin straighter than posterior margin, which is deeply curved; without slight bulge on posterior margin at level of distal edge of quadrangle; not symmetrical from lateral mid-line to apex. Length Ax2 to base of pterostigma: 22.7 mm, nodus to base of pterostigma: 17.2 mm; maximum width 9.5 mm. Pterostigma approximately 4 times longer than wide. Subnodus with reversed obliquity. 34 crossveins preserved in postnodal space (complete number), distal-most one hyperstigmal. Costal space distal to pterostigma maximum four cells wide in area preserved. Apex not preserved: RA at margin unknown. Proximal-most portion of IR1 zigzagged (most of proximal half of IR1 not preserved). RP2 : origin six cells distal to origin of IR2. IR2: origin at subnodus. RP3-4 : origin closer to middle between Ax2, subnodus. CuA terminus missing, but apparently as in holotype; CuA–A space eight wide cells at widest .

Paratype 2, SR 02-24-14 A, B, forewing ( Fig. 26 ). Missing mid-posterior margin region, portions proximal to nodus (arculus, Ax2, quadrangle). As for holotype except: length nodus to apex: 19.3 mm, origin of RP2 to apex: 15.6 mm, nodus to base of pterostigma: 14.6 mm; maximum width estimated 8.3 mm. Pterostigma three times longer than wide; subtends 5.5 cells. RA meets margin at apex. RP2 : origin six cells distal to origin of IR2. RP3-4 : origin apparently positioned similar to that of holotype (arculus, Ax2 not preserved). CuA terminus not preserved, but preserved portion as in holotype; most of CuA–A space not preserved, four wide cells at level of nodus (holotype, similar) .

Paratype 3, SR 94-05-22 A, B, forewing ( Fig. 27 ). Missing base of wing: proximal to nodus in anterior region, from level just distal to quadrangle in posterior region. As for holotype except: length nodus to apex: 22.0 mm, origin of RP2 to apex: 18.0 mm, nodus to base of pterostigma: 16.4 mm; maximum width 9.1 mm. Pterostigma four times longer than wide; subtends 6.5 cells; no oblique brace vein. 38 crossveins in postnodal space (complete number), distal-most one hyperstigmal. RA meets margin at apex. Small portion of proximal region of IR1 preserved, zigzagged. RP2 : origin relative to IR2 not preserved. IR2, RP3-4 origins, arculus not preserved. CuA–A space six wide cells at widest .

Paratype 4, SRUI 99-96-55 A, B hind wing ( Fig. 28 ). Missing most of wing proximal to nodus, middle portions of remaining, slightly torn in region of pterostigma. As for holotype except: shape of preserved portion like that of paratype 1. Length nodus to apex: 19.7 mm, origin of RP2 to apex: 16.4 mm, nodus to base of pterostigma: 14.7 mm; width 8.2 mm. Pterostigma incomplete. 31 crossveins preserved in postnodal space (complete), distal-most hyperstigmal. RA meets margin at apex. Basal portion of IR1 preserved, zigzagged. RP3-4 origin, arculus, Ax2 not preserved. CuA–A space six wide cells at widest .

Paratype 5, F-1140, hind wing ( Fig. 29 ). Missing nodal region to base. Shape relative to holotype, paratype 1 not determinable. As for holotype except: origin of RP2 to apex: 19.0 mm, width estimated 8.8 mm. Pterostigma subtends 6.5 cells; no oblique brace vein. One hyperstigmal crossvein. RP2 origin relative to that of IR2 not preserved. IR2, RP3-4 origins, arculus, Ax2 not preserved. Nodus not preserved, but CuA terminates on posterior margin at similar level as holotype; CuA–A space at least six cells wide cells at widest, probably one or two more .

Paratype 6, SR 00-04-05, hind wing ( Fig. 30 ). Missing or very damaged proximal to subnodus, missing small portion of posterior margin mid-wing. As for holotype except: shape more like paratype 1: anterior (costal) margin straight between level of origin of RP2 , subnodus, or proximal to it, near pterostigma. Length subnodus to apex: about 20.0 mm, origin of RP2 to apex: 16.9 mm, subnodus to base of pterostigma: about 14.5 mm; width 9.2 mm. Pterostigma subtends six cells. 30 crossveins preserved in postnodal space, probably 31 total, distal-most one hyperstigmal. RA not slightly upturned at margin. RP2 : origin 4.5 cells distal to origin of IR2. IR2 origin poorly preserved, apparently as in holotype. RP3-4 origin, arculus, Ax2 not preserved. CuA terminus not preserved, preserved portion as in holotype; CuA–A space six wide cells at widest .

Paratype 7, F-1044, male ( Fig. 31 ). Almost complete specimen preserved in lateral aspect: missing head, legs; all wings present, mostly overlapping, missing apical portions of two; abdomen present, segments 1 to 3 articulated to thorax; segments 4 to 10 (latter rotated so that dorsal margin is apical) and anal appendages present, disarticulated from rest of fossil, positioned closely. Wings: much of colouration of all four wings comparable, same for all. Wings somewhat crumpled, measurements not taken. Arculus immediately proximal to Ax2 (also in other two wings where preserved). Origin of RP3-4 near middle between arculus, nodus. Abdomen: about 34 mm long, about as long as wing; thick (segment 3 is 4.8 mm long, 2.4 mm wide in lateral view); segment 10 apparently displaced, rotated so that dorsal margin lies apically (about 0.5 mm long, 0.9 mm wide in lateral view), proximal parts of anal appendages thus somewhat obscured; cercus elongate, straight, slender, parallel-sided, the ventral margin slightly longer than the dorsal one, estimated at 1.3 mm long from its tip to the point it is obscured by segment 10; paraproct roughly triangular, the ventral margin about 0.8 mm long, the apical margin emarginate, more or less bifid, the ventral tooth slightly curved dorsally and acute.

Paratype 8, RBCM P1547, hind wing ( Fig. 32 ). Proximal half of a wing. All preserved portion as for holotype except: shape more like paratype 1: posterior margin around level of distal margin of quadrangle not slightly expanded. RP2: origin five cells distal to origin of IR2. IR2: origin near, proximal to subnodus. RP3-4: origin near, slightly distal to middle between arculus, subnodus. CuA–A space six wide cells at widest.

Paratype 9, RBCM P1548, hind wing ( Fig. 32 ). Proximal portion of a wing. All preserved portion as for holotype except: shape more like paratype 1: posterior margin around level of distal margin of quadrangle not slightly expanded. Proximal portion of IR1 preserved, zigzagged. RP3-4: origin in middle third between arculus to subnodus. CuA–A space five wide cells at widest in preserved portion.

Additional material:

SR 10-72-03, fore- or hind wing ( Fig. 33 ). Much of the apical half of a wing, with sections not preserved, and colouration poorly preserved. As preserved, colouration agrees with holotype. All preserved portion as for holotype except: maximum width estimated as about 9.0 mm. Pterostigma four times longer than wide; subtends 6.5 cells. Few postnodal crossveins preserved, distal-most one hyperstigmal (a second joins RA at the base of the pterostigma). Costal space distal to pterostigma maximum four cells wide. Proximal portion of IR1 preserved, zigzagged. CuA–A space six wide cells at widest.

SR 13-005-017, forewing ( Fig. 28 ). Damaged proximal portion of a wing, as for holotype except: colouration faintly preserved but apparently like that of holotype. What appears to be a possible accessory antenodal crossvein is most likely damage. RP3-4: origin in middle third between arculus, subnodus. CuA–A space apparently five wide cells at widest.

SR 17-006-001, hind wing ( Fig. 32 ). Proximal portion of a wing, as for holotype except: IR2: origin at subnodus. RP3-4: origin half way between arculus, subnodus. CuA–A space at level of subnodus three cells wide, not preserved posterior to this.

SRUI 99-71-07, fore- or hind wing ( Fig. 34 ). Apical portion of a wing. Colouration as in holotype. All other preserved morphology agrees with holotype except: distal-most postnodal crossvein hyperstigmal; pterostigma four times longer than wide; costal space distal to pterostigma maximum four cells wide. Part of proximal portion of IR1 preserved, zigzagged.

RBCM P1549, fore- or hind wing ( Fig. 34 ). Apical portion of a wing. Colouration as in holotype. All other preserved morphology agrees with holotype except: distal-most postnodal crossvein hyperstigmal; pterostigma about 3.5 times longer than wide; costal space distal to pterostigma maximum four cells wide.

SR 95-03-30, fore- or hind wing ( Fig. 33 ). An apical portion of a wing, torn, missing the pterostigmal region. As preserved, colouration agrees with holotype. Part of proximal portion of IR1 preserved, zigzagged.

SR 06-62-06, fore- or hind wing ( Fig. 30 ). Much of an apical half or a wing from just distal to nodus, crushed, crumpled, torn. Colouration agrees with holotype.

Etymology. The specific epithet is a patronymic formed from the surname of Shay Hoban, the collector of the first of the specimens of this species (paratype 2) in May of 1994, recognising his contribution.

Range and age. Republic localities B4131 and A0307 of the Tom Thumb Tuff Member of the Klondike Mountain Formation, latest Ypresian; McAbee, BC, Canada, mid-Ypresian.

Discussion. Colour patterning is well preserved in a number of fore- and hind wings. This appears consistent throughout, including McAbee and Republic specimens, except for a slight variation in the light fascia along the posterior margin from a rather evenly “U” shape (e.g., SR 94-05-22) to being slightly curved proximally (e.g., SR 11-21-33). As discussed above, we can only be confident that this is male colouration.

They also vary by size: the forewing SR 02-24-14 is smaller than the forewing SR 94-05-22 and the hind wing SRUI 99-96-55 is smaller than the hind wing SR 11-21-33. This might be explained by sexual dimorphism (e.g., Serrano-Meneses et al. 2008).

Forewings with complete CuA–A spaces are five to six cells wide (SR 94-05-22, F-1052), and hind wings vary from six to eight cells wide (SRUI 99-96-55, SR 11-21-33), consistent with their more deeply curved posterior margin. The costal space distal to the pterostigma is a maximum three cells wide, except in RBCM P1549, SR 10-72-03, SRUI 99-71-07, and SR 11-21-33, where it reaches four cells wide.

Figures

FIGURE 24. Okanagrion hobani holotype, F-1052. A, photograph; B, drawing. Both to scale, 5 mm.

FIGURE 25. Okanagrion hobani paratype 1, SR 11-21-33. A, photograph; B, drawing. Both to scale, 5 mm.

FIGURE 26. Okanagrion hobani paratype 2, SR 02-24-14. A, photograph; B, drawing. Both to scale, 5 mm.

FIGURE 27. Okanagrion hobani paratype 3, SR 94-05-22. A, photograph; B, drawing. Both to scale, 5 mm.

FIGURE 28. Okanagrion hobani. Paratype 4, SRUI 99-96-55: A, photograph; B, drawing; SR 13-005-017: C, photograph; D, drawing.All to scale, 5 mm.

FIGURE 29. Okanagrion hobani paratype 5, F-1140. A, photograph; B, drawing. Both to scale, 5 mm.

FIGURE 30. Okanagrion hobani. Paratype 6, SR 00-04-05:A, photograph; B, drawing; SR 06-62-06:A, photograph; B, drawing. Both to scale, 5 mm

FIGURE 31. Okanagrion hobani paratype 7, F-1044. A, photograph of complete specimen; B, close-up of anal appendages; C, drawing of abdominal showing segments 8 to 10 (10 apparently displaced and rotated somewhat clockwise in the view), paraprocts and one cercus; D, close-up showing proximal portions of wings; E, colour-coded wings referring to 22F through H; F, G, H: drawings of wings indicated in 22E: F, green wing, G, red wing; H, blue wing (purple wing very damaged, not informative). A to scale, B–H to scale; scale bars are 5 mm

FIGURE 32. Okanagrion hobani. Paratype 9, RBCM P1548: A, photograph; B, drawing. Paratype 8, RBCM P1547: C, photograph; D, drawing. SR 17-006-001: E, photograph; F, drawing. All to scale, 5 mm.

FIGURE 33. Okanagrion hobani. SR 10-72-03: A, photograph; B, drawing. SR 95-03-30: C, photograph; D, drawing. All to scale, 5 mm.

FIGURE 34. Okanagrion hobani. SRUI 99-71-07: A, photograph; B, drawing. RBCM P1549: C, photograph; D, drawing. All to scale, 5 mm.

FIGURE 35. Okanagrion hobani relatively complete wings, comparative forewings (FW) and hind wings (HW). Red, blue arrows, see text. All to scale, 5 mm.