The Cephalozygoptera, a new, extinct suborder of Odonata with new taxa from the early Eocene Okanagan Highlands, western North America
Author
Archibald, Bruce
Author
Cannings, Robert A.
0000-0001-9491-8186
annings@royalbcmuseum.bc.ca
Author
Erickson, Robert J.
0000-0003-1162-0355
1990platypus@gmail.com
Author
Bybee, Seth M.
0000-0001-6224-6303
seth.bybee@gmail.com
Author
Mathewes, Rolf W.
0000-0001-7637-199X
r_mathewes@sfu.ca
text
Zootaxa
2021
2021-02-24
4934
1
1
133
journal article
7439
10.11646/zootaxa.4934.1.1
300bac18-55f5-4e34-90e1-7fccd02d68c1
1175-5326
4558796
79895443-4597-42A5-AF8A-023EACB20E10
Okanagrion liquetoalatum
Archibald & Cannings
,
new species
Fig. 38
.
Diagnosis.
Wings separated from those of
O
.
hobani
,
O
.
threadgillae
,
O. worleyae
,
O
.
dorrellae
,
O
.
beardi
by shape: length (arculus to apex) / maximum width 2.6 [
O
.
hobani
: 3.2;
O
.
threadgillae
: 3.0, 3.1;
O. worleyae
holotype
: 2.8,
paratype
: 3.1;
O
.
dorrellae
: 3.7;
O
.
beardi
: 3.3, 3.4]; from
O
.
angustum
by shape [
O. lochmum
,
O. worleyae
,
O
.
angustum
apical region not preserved, but
O
.
angustum
distinctly narrower, see width, angle of posterior to anterior margin preserved between levels of nodus, origin of RP2]; 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
.
lochmum
by cells less dense apically: RA–RP1 space two cells wide distal to 1–2 cells proximal to pterostigma [
O
.
lochmum
from 7–8 cells proximal to pterostigma], RA–RP1 space three cells wide distal from apical corner of pterostigma or one cell distal from that [
O
.
lochmum
from about one cell proximal to pterostigma], RA–RP1 space becomes five cells wide over half distance from pterostigma to margin [
O
.
lochmum
: from distal end of pterostigma]; from
O. hobani
by main veins less deeply curved near margin; from
O. dorrellae
by MP linear to terminus [
O. dorrellae
: zigzagged distally]; from
O
.
angustum
,
O. beardi
by IR2 origin between RP1-2, RP3-4 [
O
.
angustum
,
O. beardi
: origin on RP1-2].
Further separated by colouration (sex unknown):
O. liquetoalatum
: hyaline throughout; others with distinct colour patterning as in their diagnoses;
O. worleyae
: lightly infuscate throughout known wing.
Type material.
Holotype
: SR 06-69-17
A
, B (
Fig. 38
), collected at
Republic B
4131 by
Gregg Wilson
,
29.iv.2006
: a well preserved disarticulated wing, housed in the
Stonerose Interpretive
Center
collections.
Description.
Holotype
, SR 06-69-17A, B, wing. Shape: oval distal to nodus, anterior margin rather straight between nodus, pterostigma, posterior margin evenly curved apical to petiole. Hyaline throughout. Length
30.5 mm
, arculus to apex:
25.2 mm
, nodus to apex:
20.3 mm
, origin of RP2 to apex:
16.6 mm
, arculus to base of pterostigma:
20.4 mm
, nodus to base of pterostigma:
15.4 mm
, nodus at 29% wing length; maximum width
8.5 mm
. Pterostigma 3.5 longer than wide, subtends 5.5 cells, no oblique brace vein. Costal space distal to pterostigma maximum 3 cells wide; RA terminates at apex, slightly upturned at margin. 31 crossveins in postnodal space, none hyperstigmal, those in postsubnodal spaces not aligned. Maximum three cells wide distal to pterostigma in costal space. RA–RP1 space hardly narrows near margin. RP1–IR1 space goes to two cells wide eight cells distal to origin of IR1. IR1: origin eight cells distal to origin of RP2, zigzagged proximally. IR1 two cells wide six (or ten?) cells distal to origin. RP2: origin 5.5 cells distal to that of IR2. IR2: origin very close proximal to subnodus. RP3-4 origin near, distal to middle between arculus, nodus. Arculus at Ax2. No crossvein O. All main veins except base of IR1 linear. CuA–A space with five cells wide at widest.
Etymology
. The specific epithet
liquetoalatum
is formed from the Latin
liquet
for clear and
alatus
(
-a, -um
) meaning winged.
Range and age
. Republic locality B4131 of the Tom Thumb Tuff Member of the Klondike Mountain Formation; latest Ypresian.
Discussion.
Wing falsely appears mottled in
Fig. 38
photo by wetting with ethanol.