Dysagrionites delinei 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 : 104-106

Dysagrionites delinei Archibald & Cannings , new species

Figs. 62–63A .

Diagnosis. Wings of Dysagrionites delinei may be distinguished from those of all other species of Dysagrioninae except of Okanopteryx , Stenodiafanus by: Cu–A space 3 cells wide [ Okanagrion : 4–7; Furagrion , Dysagrionites sp. A, Stenodiafanus : 2 (most likely, wing incomplete); Dysagrion , Phenacolestes : 4; Electrophenacolestes , 4 (one column 5); Okanopteryx : 2–4; not separated from Primorilestes : 3–5; Dysagrionites sp. B: probably 3 but unclear]. By CuA zigzagged beyond about level of origin of RP2 [ Electrophenacolestes , Primorilestes , Okanagrion : linear; not separated from Dysagrion , Okanopteryx , Phenacolestes , Stenodiafanus ]. Separated from the sole species of Stenodiafanus by wider wing, 6.5 mm wide [5.8 mm]; by CuA–A space maximum three cells wide [two]. Separated from males of Okanopteryx , Okanagrion (males of O. hobani , sex unknown in other species) except O. liquetoalatum , Dysagrionites species B (sex unknown) by wing hyaline throughout known portion (from base past presumed mid-way between nodus, pterostigma [ Okanopteryx , Okanagrion except O. liquetoalatum , Dysagrionites species B: with infuscate regions]. Further distinct from Primorilestes by no intercalary vein in CuA–A space. Most easily separated from fossil genera regarded here as possible Dysagrionidae by: from Chickaloon specimen by cells of CuA–A evenly sized, spaced, maximum three wide [irregularly sized, spaced, four wide]; Thanetophilosina by all preserved crossveins in postnodal, postsubnodal spaces aligned or almost so [not]; from NHMUK I.9866/I.9718 by origin of RP3-4 about a third distance from subnodus to level of anterio-distal corner of quadrangle [about 20%]; distinct from cf. Dysagrionidae genus A, species A ( Petrulevičius et al. 2008) by hyaline membrane [infuscate except apex distal to pterostigma]; CuA lightly zigzagged distal to level of origin of RP2 [linear].

Material. Holotype: SR 06-01-46AB ( Fig. 62 ), collected at Republic B 4131 by William Deline, 21.ix.2005, housed in the Stonerose Interpretive Center collections; paratype 1: UWBM 77612 ( Fig. 63A ), collected at Republic, no exposure, collector, or date recorded, in the Burke Museum collections; paratype 2: SR 94-05-26 ( Fig. 62 ), collected at Republic B 4131 by Analee Flowers, 18.x.1994, in the Stonerose Interpretive Center collections.

Description. Holotype, SR 06-01-46, wing. Missing apical portion from proximal to pterostigma. Approximately 6.5 mm maximum width. Hyaline throughout (sex unknown). All preserved crossveins in postnodal, postsubnodal spaces aligned or almost so. RP1–IR1, IR1–RP2 spaces do not become two cells wide in preserved portion. IR1: origin four cells distal to origin of RP2. RP2: origin almost five cells distal to origin of IR1. IR2: origin at subnodus. RP3-4: origin not preserved. MA with only slight zigzag around level of origin of IR1. MP linear, slightly curved from quadrangle (distal portion not preserved). CuA becomes slightly zigzagged around level of nodus, increasingly so apical to level of origin of RP2. CuA–A space three cells at widest (from close distal to level of nodus to level of origins of IR1), 9–10 columns; two cells wide proximal to this about 4 columns, distal to this a few columns of two cells wide, then not preserved.

Paratype 1, UWBM-77612, wing. Proximal portion missing apical portion from mid-wing. Maximum width not measurable, but preserved portions match SR 06-01-46. Hyaline throughout (sex unknown). Three preserved crossveins in proximal postnodal, postsubnodal spaces aligned. RP1 –IR1, IR1– RP2 spaces do not become two cells wide in preserved portion. IR1 not preserved. RP2 : origin probably five cells distal to origin of IR1. IR2: origin at subnodus. RP3-4 : origin just over 2/3 distance from arculus to subnodus. MA with only slight zigzag around similar length as SR 06-01-46. MP linear, slightly curved from quadrangle (distal portion not preserved). CuA becomes slightly zigzagged around level of nodus, increasingly so apical to approximate level of origin of RP2 . CuA–A space two cells wide from level of nodus to half way between level of nodus, presumed origin of RP2 ; three cells wide 6–7 columns, then briefly two for remaining preserved portion .

Paratype 2, SR 94-05-26, wing. Anterior portion missing apical region proximal region, much of posterior region. Hyaline throughout (sex unknown). All preserved crossveins in postnodal, postsubnodal spaces aligned or almost so, two in nodal space without matching subnodal space crossveins. RP1 –IR1 space becomes two cells wide six cells distal to origin of IR1. IR1: origin three cells distal to origin of RP2 ; IR1– RP2 space does not become two cells wide in preserved portion. RP2 : origin apparently 3.5 cells distal to origin of IR1. IR2: origin at subnodus. RP3-4 : origin 2/3 length of arculus to subnodus. MA notably zigzagged beyond level of origin of IR1. MP: small portions preserved, linear. CuA slightly zigzagged around level of origin of RP2 , then increasingly so in remaining preserved portion. CuA–A space at least three cells wide at least seven columns, maybe (many?) more, all preserved portion at least two .

Etymology. The specific epithet formed from the surname of William Deline, collector and donor of the holotype, recognising his contribution.

Range and age. Tom Thumb Tuff Member of the Klondike Mountain Formation at Republic, Washington, USA, all with exposure information are from B4131; late Ypresian.

Discussion. This species might belong to either Okanopteryx or Okanagrion , expanding its genus concept, or may constitute a new orthotaxon genus.

These differ among themselves by the width of the CuA–A space: SR 06-01-46 is three cells wide between the origins of RP2 and IR1, SR 96-12-03 is three cells wide only briefly around the level of the origin of RP2, and in UWBM-77612 it is uniformly two cells wide except for one column of three. This suggests that there may be more than one species among these specimens.

Although SR 96-12-03 is the middle portion of a wing lacking almost all diagnostic character states of the Dysagrionidae listed above, its great similarity to the other two specimens in particular makes it possible to assign it to the family. It does differ in having almost the whole preserved CuA–A space two cells wide, whereas in the other specimens it has many columns of three. If this specimen is not a member of this species, we believe it likely closely related.

Figures

FIGURE 62. Dysagrionites delinei holotype, SR 06-01-46. A, photograph; B, drawing; paratype 2, SR 94-05-26: C, photograph; D, drawing.All to scale, 5 mm.

FIGURE 63. Dysagrionites delinei paratype 1, UWBM 77612. A, photograph; B, drawing; Dysagrionites sp. A, SR 96-12-03: C, photograph; D, drawing. All to scale, 5 mm.