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 lochmum Archibald & Cannings , new species Fig. 23 . Diagnosis. Wings separated from those of O. worleyae by shape: posterior margin more deeply curved ( O . angustum not known by preservation); 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. hobani by RP2, IR2, RP3-4, MA, MP not as strongly curved at margin (veins anterior to these not preserved at margin); from O. hobani by main veins less deeply curved near margin; from O. threadgillae by IR2–RP3-4 space at wing margin about half width as in O. threadgillae ; from O . angustum , O. dorrellae by width measured two cells proximal to origin of RP2 perpendicular to apical margin [ O . angustum , O. dorrellae : 75% width of O . lochmum ]; from O . dorrellae by MP linear to margin [ O . dorrellae : zigzagged near margin]; from O . angustum , O. beardi by IR2 origin between RP1-2, RP3-4 [ O . angustum , O. beardi : origin on RP1-2]; from O. threadgillae , O. beardi , O. dorrellae , O. hobani , O. liquetoalatum , O. worleyae by cells denser in apical wing: RA–RP1 space becomes two cells wide just over seven cells proximal to pterostigma [ O. threadgillae , O. beardi , O. dorrellae : about three cells proximal to it; O. hobani : about two to four; O. liquetoalatum : one; O. worleyae four]; RA–RP1 space three cells wide from about one cell proximal to pterostigma [ O. threadgillae , O. hobani , O. liquetoalatum , O. worleyae : at or one cell from apical corner of pterostigma; O. beardi : two–three cells apical to pterostigma; O . angustum , O. dorrellae : not known]; RA–RP1 space becomes four/five cells wide at distal corner of pterostigma [ O. hobani : from about half distance from pterostigma to margin; O. beardi : becomes maximum four wide about four–five cells distal to pterostigma; O. liquetoalatum : five cells wide over half distance from pterostigma to margin; O. worleyae : maximum four wide from about four or more cells distal to pterostigma; O . angustum , O. dorrellae : not known by preservation]. Further separated by colouration (sex unknown): similar to that of O. beardi , and differing from other species of the genus as in their diagnoses. Type material. Holotype : RBCM 11799.001 ( Fig. 23 ), collected at the McAbee Hoodoo Face beds by John Leahy , date unknown: a mostly complete wing missing the apical-most portion and small damage proximally; housed in the Royal British Columbia Museum collections. Description. Holotype , RBCM 11799.001, hind wing. Shape generalised for Okanagrion hind wing, i.e ., anterior margin nodus to pterostigma rather straight, posterior margin deeply curved; length arculus to base of pterostigma: 20.4 mm ; nodus to base of pterostigma: 15.4 mm ; nodus estimated at about 28% wing length; maximum width 8.5 mm ; colouration as in diagnosis; pterostigma anterior, posterior margins oblique (anterior margin more), three times longer than wide, subtends 5.5 cells; no oblique brace vein; crossveins in postnodal, postsubnodal spaces not aligned; maximum four cells wide distal to pterostigma in costal space (but region damaged); RA–RP1 space maximum five cells wide in preserved portion; IR1 origin six cells distal to origin of RP2; RP2 origin five cells distal to origin of IR2; IR2 origin close to subnodus, immediately proximal to it; RP3-4 origin in distal part of middle third between arculus, nodus; arculus at Ax2; Ax0 not detected; no crossvein O; MA linear (very slight, short zigzag); MP linear, hardly curved from quadrangle to terminus about two-thirds distance from nodus to pterostigma; MP, CuA sub-parallel at terminus on posterior margin; CuA linear; CuA–A space with seven cells at widest (between levels of origins of IR1, RP2). Etymology . The specific epithet lochmum is the Latinized neuter adjective form of the Greek Λóχμη, lóchmi , meaning thicket , referring to the denseness of the crossvenation. Range and age . McAbee, BC, Canada ; mid-Ypresian.