Aeshna Fabricius, 1775
|
publication ID |
https://doi.org/ 10.5252/z2011n4a8 |
|
persistent identifier |
https://treatment.plazi.org/id/03F2BF4D-3256-B81B-FC91-2960FBECF916 |
|
treatment provided by |
Felipe |
|
scientific name |
Aeshna Fabricius, 1775 |
| status |
|
Genus Aeshna Fabricius, 1775 View in CoL
TYPE SPECIES. — Libellua grandis Linnaeus, 1758 (recent).
Aeshna shanwangensis Li, Nel & Ren , n. sp. ( Figs 10 View FIG ; 11 View FIG )
TYPE MATERIAL. — Holotype no. CNU-ODO-SS2011011 (one well preserved specimen, with both pairs of wings nearly complete combining with partly preserved thorax,
veins and pterostigma dark brown, wings hyaline), deposited at the College of Life Science, Capital Normal University, Beijing, China.
AGE AND OUTCROP. — Shanwang Formation, Middle Miocene. Shanwang Village, Linqu County, Shandong Province, China.
DIAGNOSIS. — Wing characters only. Anal triangle three-celled and with basal side curved; transversely elongated anal loop with 12 or more cells; fork of IR2 well basal of pterostigma, with four rows of cells between its two branches in widest part; Rspl and Mspl with strong concave bend, with four to five rows of cells in areas between Rspl and IR2 as well as Mspl and MA at widest parts; space between MP and CuA at basal third in hindwing twice as wide as at distal third; hindwing membranule as long as one-third to half of anal wing margin.
ETYMOLOGY. — Named after Shanwang Village where the fossil was discovered.
DESCRIPTION
Forewing 47.8 mm long, width at level of nodus 11.9 mm; distance from wing base to Ax1 3.8 mm, to Ax2 8.8 mm, to arculus 6.1 mm, to nodus 20.7 mm; distance from nodus to base of pterostigma 13.1 mm, to level of fork of IR2 15.3 mm; pterostigma 4.1 mm long and 0.6 mm wide, covering four cells; pterostigma brace oblique, well aligned with basal side of pterostigma; Ax1 very oblique, with five antenodal crossveins between it and Ax2; Ax2 straight; fourteen postnodal crossveins not aligned with sixteen postsubnodal crossveins; arculus angled, sectors of arculus arising near its middle; IR1 short, originating from level of mid pterostigma, with three rows of cells between it and RP1; RP1 and RP2 strictly parallel to level of mid pterostigma, with one row of cells in between; RP2 evenly curved toward posterior wing margin at level of distal half of pterostigma; two rows of cells between RP1 and RP2 beneath pterostigma; RP2 and anterior branch of IR2 more or less parallel with only one row of cells between them, then distally constricted; IR2 symmetrically forked 2.3 mm basal of basal side of pterostigma, four rows of cells in area between forks of IR2; Rspl strongly curved, area between Rspl and posterior branch of IR2 with four to five rows of cells in widest part, but distally constricted and with only one row of cells; RP3/4 and MA more or less parallel, with one row of cells in between basally, but two rows of cells after “aeshnid bulla”; MA with a concave bend at level of “aeshnid bulla” (i.e. a characteristic oblique brace between RP3/4 and MA) very pronounced; one oblique vein “O” slightly distal of base of RP2; Mspl strongly curved and a concave bend at distal portion, area between Mspl and MA with four rows of cells in widest part, but distally constricted and with only one row of cells; MP shortened, ending on posterior wing margin nearly at level of nodus; CuA with five weak branches; basal part of area between MP and CuA with only one row of cells; median space free; submedian space crossed by six crossveins, including CuP; PsA not stronger than other crossveins in submedian space, no well defined subdiscoidal triangle; hypertriangle elongated, 7.3 mm long, five-celled; discoidal triangle elongated, 5.0 mm long and 2.2 mm wide (basal side 2.5 mm and costal side 5.8 mm long), six-celled in left forewing but five-celled in right forewing; trigonal planate present but not very distinct; anal area with two rows of cells, with first row of cells larger than second row.
Hindwing 47.2 mm long, width at level of nodus 14.8 mm; distance from wing base to Ax1 4.1 mm, to Ax2 9.2 mm, to arculus 5.5 mm, to nodus 18.3 mm; distance from nodus to base of pterostigma 18.0 mm, to wing apex 28.3 mm, to level of fork of IR2 14.6 mm; pterostigma 4.4 mm long and 0.7 mm wide, covering three cells; pterostigma brace oblique, well aligned with basal side of pterostigma; Ax1 and Ax2 not oblique, with five or four antenodal crossveins between them; eight secondary antenodal crossveins not aligned with seven antesubnodal crossveins, distal of Ax2; 15 postnodal crossveins not aligned with 20 postsubnodal crossveins; arculus angled, sectors of arculus arising near its middle; IR1 short, originating below basal half of pterostigma, with two-three rows of cells between it and RP1; RP1 and RP2 strictly parallel to level of mid pterostigma, with one row of cells in between; RP2 and anterior branch of IR2 more or less parallel with only one row of cells between them, then distally constricted; RP2 bend toward posterior wing margin at level of distal half of pterostigma; two rows of cell between RP1 and RP2 beneath pterostigma; IR2 symmetrically forked, 2.7 mm basal of basal side of pterostigma, four rows of cells in area between forks of IR2; Rspl strongly curved, area between Rspl and posterior branch of IR2 with four-five rows of cells in its widest part, but distally constricted and with only one row of cells; RP3/4 and MA more or less parallel, with one row of cells in between basally, but two rows of cells after “aeshnid bulla” and three rows of cells in widest part; one oblique vein “O” slightly distal of base of RP2; Mspl strongly curved, area between Mspl and MA with four-five rows of cells in widest part, but distally constricted and with two rows of cells; MP shortened, ending on posterior wing margin at level of nodus; CuA with five weak branches; area between MP and CuA with two rows of cells in basal half, and basal part twice as wide as distal part; MP and CuA converging towards wing margin; median space free; submedian space crossed by five crossveins, including CuP; CuP-crossing strong, aligned with AA2b; PsA not stronger than other crossveins in submedian space, no well defined subdiscoidal triangle; hypertriangle elongated (5.8 mm long) but apparently shorter than in forewing, five-celled; discoidal triangle elongated, 4.0 mm long and 2.3 mm wide (basal side 2.5 mm and costal side 4.3 mm long), but apparently shorter than in forewing, five-celled; trigonal planate short, immediately bend toward MP; anal loop pentagonal, transversely elongated, 12-celled in right hindwing and 13-celled in left hindwing; gaff prolonged and straight, 2.9 mm long; basal side of anal loop straight and long, about 5.7 mm long; anal triangle well defined (male specimen), very narrow, three-celled and with basal side curved; membranule well defined but short, about as long as 1/2-1/3 of anal wing margin.
Aeshna forficatum Li, Nel & Ren , n. sp. ( Figs 12 View FIG ; 13 View FIG )
TYPE MATERIAL. — Holotype No. CNU-ODO-SS2011012 (a pleated forewing and a partly preserved hindwing partly overlapped, both coloured with sandy beige, pterostigma black or puce, venation black), deposited at the College of Life Science , Capital Normal University, Beijing, China.
AGE AND OUTCROP. — Shanwang Formation, Middle Miocene, Shanwang Village, Linqu County, Shandong Province, China.
DIAGNOSIS. — Wing characters only. Wings uniformly sandy beige coloured; slightly curved pterostigmal brace very oblique and long; Ax1 and Ax2 both oblique in forewing; arculus angled, sectors of arculus arising from its upper end; fork of IR2 well basal of pterostigma, with four rows of cells between its two branches; discoidal triangle rather elongated, with costal side about 2.8 times as long as basal side; Rspl and Mspl with strong concave bend, with four to five rows of cells in areas between Rspl and IR2 as well as Mspl and MA in widest parts.
ETYMOLOGY. — Name after the Latin word “ forficatus ” to reflect the shape of the partly overlapped wings.
DESCRIPTION
Forewing 55.5 mm long, width unknown; distance from wing base to Ax1 4.2 mm, to Ax2 10.8 mm, to arculus 6.7 mm, to nodus 26.7 mm; distance from nodus to base of pterostigma 22.6 mm, to level of fork of IR2 17.0 mm; pterostigma 4.3 mm long and 0.7 mm wide, covering four cells; pterostigma brace very oblique and long, slightly curved, well aligned with the basal of pterostigma; Ax1 and Ax2 oblique, with five antenodal crossveins between them; 17 secondary preserved antenodal crossveins not aligned with antesubnodal crossveins, distal of Ax2; 15 postnodal crossveins not aligned with 17 postsubnodal crossveins; arculus angled, sectors of arculus arising from its upper end; IR1 short, originating from level of distal half of pterostigma; RP1 and RP2 strictly parallel to level of mid pterostigma, with one row of cells in between; RP2 smoothly bend toward posterior wing margin at level of mid pterostigma; two rows of cells between RP1 and RP2 beneath pterostigma; RP2 and anterior branch of IR2 more or less parallel with only one row of cells between them, then distally constricted; IR2 symmetrically forked, 5.0 mm basal of basal side of pterostigma, four rows of cells in area between forks of IR2; Rspl strongly curved, area between Rspl and posterior branch of IR2 with four-five rows of cells in its widest part, but distally constricted and with only one row of cells; RP3/4 and MA more or less parallel, with one row of cells in between basally, but two rows of cells after “aeshnid bulla”, and three rows of cells at level of “aeshnid bulla”; at “aeshnid bulla” a well defined characteristic oblique brace between RP3/4 and MA; one oblique vein “O” slightly distal of base of RP2; Mspl strongly curved, area between Mspl and MA with four rows of cells in widest part, but distally constricted; strong secondary intercalary veins between Rspl and IR2 and between Mspl and MA; numerous secondary intercalary veins originating from Rspl and Mspl; basal area between MP and CuA with only one row of cells; median space free; submedian space crossed by several crossveins but number unknown; hypertriangle narrow and long, 9.0 mm long, fivecelled; six-celled discoidal triangle rather elongated, about 7.3 mm long and 2.3 mm wide (basal side about 2.8 mm and costal side about 7.8 mm long); anal area with two rows of cells, with cells of first row distinctly larger than those of second row.
Hindwing preserved wing length 52.0 mm, 14.3 mm wide at the distal third; pattern of venation very similar to that of forewing in distal half of wing, except for the broader wing; unfortunately the cubito-anal area is not preserved so it is impossible to determine the structure of anal loop and anal triangle and to determine the sex of the specimen.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.