Guocordulia boreala Nel & Huang & Lian 2024, comb. nov.

Guocordulia boreala (Ren & Guo, 1996), comb. nov. for Mesocordulia boreala Ren & Guo, 1996 (Figs 1, 2) Material. Holotype LB94021 (female), paratype LB94022 (hind wing), Geological Museum of China, Beijing. New specimen: NIGP206353 (complete female in dorsal view). Diagnosis (new diagnosis for genus and species). Compound eyes well separated; forewing secondary antenodals incomplete; hind wing antenodals complete; five crossveins in forewing antesubnodal area, only one in hind wing; sector of arculus well separated; a well-defined elongated anal loop with ten cells; PsA well defined in fore- and hind wings; six postnodal crossveins; subdiscoidal vein (basal part of CuA that is aligned with the distal side MAb of discoidal triangle) reduced in hind wing; hind wing CuA shortened with only one distinct dichotomic branching into CuAa and CuAb; forewing Ax2 situated distinctly above mid part of discoidal triangle; pterostigmal brace vein shifted distally beneath pterostigma. Locality and horizon. Huangbanjigou, Beibiao City, West Liaoning, NE China; Lower Cretaceous Yixian Formation (ca. 125 Ma, lower Barremian). Description. Specimen NIGP206353. Head 5.0 mm long, 3.5 mm wide, compound eyes large, 0.5 mm apart; ocelli disposed in triangle; thorax robust, 8.5 mm long, 5.2 mm wide; legs rather short and robust with strong spines, very similar to those of an extant Corduliidae; fore-, mid-, hind legs uniform, metafemur distinctly larger than mesofemur, the latter distinctly larger than fore femur, inner edge bearing two longitudinal ridges covered with spines; tibiae distinctly longer than femora, metatibiae distinctly larger than mesotibiae, mesotibiae slightly larger than foretibiae, all tibiae armed with several rows of longitudinal spines, inner edges bearing a row of long spines, ca. 8; tarsi with three tarsomeres, first tarsomere very short, second long, widened apically, third tarsomere elongate, longer than first and second tarsomeres together; paired claws small. Abdomen 29.3 mm long, 3.7 mm wide, with transverse hyaline band on segments I and II; segment II without secondary genital organs (female), cerci small, no ovipositor visible. Wing hyalines. Forewing (Fig. 2) 24.0 mm long, width opposite nodus 6.4 mm, distance from base to arculus 2.9 mm, from base to nodus 12.7 mm; from nodus to pterostigma 6.9 mm; from nodus to wing apex 8.9 mm; nodus nearer to apex than base of wing; pterostigma short, strong and covering one cell, about 1.6 mm long, 0.5 mm wide and with proximal and distal sides rather strongly divergent; pterostigmal brace distinctly oblique, slightly distal to basal side of pterostigma; Ax1 and Ax2 stronger than secondaries, 2.3 mm apart, four secondaries of first row not aligned with the three of second row; six postnodal crossveins; two proximal postnodal crossveins incomplete; arculus in a proximal position, only 0.9 mm distal of first antenodal crossvein and 0.5 mm basal of discoidal triangle; MA and RP clearly separated at their bases in arculus; free isosceles discoidal triangle, with anterior side straight; anterior side 1.6 mm long, proximal side 1.8 mm, distal side 1.8 mm; hypertriangle and median space free, MA arcuate at base; submedian space crossed by CuP; submedian and subdiscoidal spaces clearly separated by a strong oblique vein PsA; subdiscoidal space free; anal area not very broad, with two rows of cells; CuA not very long, with four posterior branches and reaching posterior wing margin slightly basal to level of nodus; three rows of cells in cubito-anal area; postdiscoidal area narrow, with two rows of cells distal of triangle, not widened near posterior wing margin, with four rows of small cells; no Bq crossvein and no crossvein in proximal part of area between RP3/4 and IR2, basal of nodus; five antesubnodal crossvein in space between RA and RP; no distinct Rspl; base of RP2 opposite subnodus; oblique crossvein ‘ O’ 0.8 mm, one cell distal of subnodus; area between IR2 and RP2 slightly narrowed distally, these veins converging near posterior wing margin; area between RP2 and RP1 narrow, with four rows of cells at most and a short but distinct vein IR1, no sigmoidal crossvein in proximal part of area between RP2 and RP1; no Mspl; MA and RP3/4 undulate, more or less parallel and directed obliquely to posterior wing margin. Hind wing (Fig. 13) 23.5 mm long, 8.8 mm wide; width opposite nodus 8.0 mm; distance from base to arculus 2.7 mm, from base to nodus 9.6 mm, from nodus to pterostigma 9.3 mm, from nodus to apex 14.3 mm; nodus in a proximal position between base and apex; pterostigma 2.4 mm long, 0.7 mm wide, short, covering one cell and with proximal and distal sides divergent; pterostigmal brace distinctly oblique, slightly distal to basal side of pterostigma; three antenodal crossveins, all of same strength; five postnodal crossveins with the three proximal incomplete; arculus in a proximal position, just distal of first antenodal crossvein and nearly opposite discoidal triangle; MA and RP clearly separated at their bases in arculus; free isosceles discoidal triangle, with anterior side slightly curved; length of anterior side 2.0 mm, of proximal side 1.2 mm, of distal side 1.9 mm; hypertriangle and median space free; MA strongly arcuate at base; submedian space crossed by CuP, a free subdiscoidal space and a distinct oblique vein PsA; anal area wide, with eight rows of cells between AA and posterior wing margin; AA with three perpendicular branches directed towards posterior wing margin, no anal triangle; no anal angle distal branch of AA provides the basal side for a long and narrow ten-cells anal loop, 5.0 mm long, 1.3 mm wide, with a ill-defined zigzagged midrib; subdiscoidal vein (basal part of CuA that is aligned with the distal side MAb of the discoidal triangle) strongly reduced; gaff of CuA elongated and slightly curved; CuAa distally zigzagged, not very long, with no well-defined posterior branches, and reaching posterior wing margin well basal of nodus level; six rows of cells in cubito-anal area; postdiscoidal area narrow, distinctly broader near posterior wing margin, with two rows of cells in proximal part and 12 rows of cells along posterior wing margin; Mspl rudimentary; MA and RP3/4 not undulating, parallel and obliquely reaching posterior wing margin; no Bq crossvein; no crossvein in proximal part of area between RP3/4 and IR2, basal of nodus; only one antesubnodal crossvein in space between RA and RP; no distinct vein Rspl; base of RP2 opposite subnodus; oblique crossvein ‘ O’ 0.9 mm distal of subnodus; area between IR2 and RP2 slightly narrowed distally; IR2 and RP2 directed obliquely to posterior wing margin; area between RP2 and RP1 with 3–4 rows of cells; a short IR1, no sigmoidal crossvein in proximal part of area between RP2 and RP1.