Tarsophlebia minor, Fleck & Bechly & Martínez-Delclòs & Jarzembowski & Nel, 2004

Fleck, Günther, Bechly, Günter, Martínez-Delclòs, Xavier, Jarzembowski, Edmund A. & Nel, André, 2004, A revision of the Upper Jurassic-Lower Cretaceous dragonfly family Tarsophlebiidae, with a discussion on the phylogenetic positions of the Tarsophlebiidae and Sieblosiidae (Insecta, Odonatoptera, Panodonata), Geodiversitas 26 (1), pp. 33-60 : 40-41

Tarsophlebia minor n. sp. ( Fig. 2 )

HOLOTYPE. — Specimen No. 55 in coll. Carpenter of MCZ, which is labelled “ Agrion spec. - Solenhofen - Dr. Krantz ”.

ETYMOLOGY. — Named after the relatively small size (hind wing length only about 26 mm), compared to the other species of the same genus.

GEOLOGICAL SETTING. — Hybonotum-Zone, Solnhofen Formation (Solnhofen Lithographic Limestone), lower Tithonian, Upper Jurassic (“Oberer Weissjura”, Malm ξ 2b), Eichstätt area, near Solnhofen, southern Frankonian Alb, Bavaria, SW Germany.

DIAGNOSIS. — This new species is distinguished by its distinctly smaller size than T. eximia (fore wing about 26 mm long instead of 35-41 mm long in T. eximia ). Also, the angle between MAb and MP + CuA is distinctly more opened than in the fore wing of T. eximia .

DESCRIPTION

The holotype is an isolated left fore wing with missing apex. Length of preserved part, 25.0 mm, probable length of wing, about 26.0 mm; although the venation is rather poorly preserved, some characters can be determined with accuracy. Wing probably hyaline, pterostigma dark brown; distance from base to arculus, 3.2 mm; from arculus to nodus, 7.8 mm; from nodus to pterostigma, 10.3 mm, pterostigma elongated and narrow, about 3.5 mm long, 0.5 mm wide, not basally recessed; pterostigmal brace oblique and strong, opposite pterostigma base; median and submedian areas free of cross-veins; CuP strongly curved, basal of Ax2, basally closing subdiscoidal space; at least primary antenodal brace and Ax2 stronger than secondary antenodal cross-veins; arculus slightly opposite Ax2; only few secondary antenodal cross-veins preserved distal of Ax2, probably less than 10 in the living animal; all secondary antenodal cross-veins not aligned with the cross-veins of second rank between ScP and RA; MP + CuA strongly curved just before its fusion with MAb; a sharp angle between MP + CuA and MAb, but more opened than in T. eximia ; no fusion between MAb and MP + CuA before CuA separates from MP. Thus it is a fore wing, as the tarsophlebiid hind wings have such a long fusion; RP + MA, MA and MAb, MP + CuA + MAb, and basal free part of CuA well aligned in arculus, as in other Tarsophlebiidae ; discoidal space basally opened; subdiscoidal area divided into two cells by a cross-vein; AA without any strong posterior branches; anal area with two or three rows of cells; posterior wing margin rounded; petiole short, about 0.8 mm long; AA reaching free part of CuA at sharp angle; no CuAb (sensu Fleck et al. 2003); CuA without strong posterior branches; less than five rows of small cells between CuA and posterior wing margin; “postero- CuA vein” and “antero-CuA vein” not preserved; CuA reaching posterior wing margin just basal to nodus level; area between MP and CuA with one row of cells in its basal part but greatly widened in its distal half; postdiscoidal area slightly widened distally; bases of RP3/4 and IR2 between arculus and nodus, distinctly nearer to nodus, base of RP3/4 3.5 mm from nodus; base of IR2 apparently on RP3/4; nodal Cr and subnodus strongly oblique; base of RP2 aligned with subnodus; oblique vein “O” three small cells distal of base of RP2; numerous Bq cross-veins; less than 11 postnodal cross-veins between C and RA, not aligned with the postsubnodal cross-veins; IR1 well defined, not zigzagged and only slightly curved; one row of cells between RP1 and IR1; area between RP2 and IR2 distinctly widened distally, “antero-IR2” and “postero-IR2” veins not preserved; area between IR2 and RP3/4 distally widened; area between RP3/4 and MA distally widened; “antero-MA” and “postero-MA” veins not preserved.

Genus Turanophlebia Pritykina, 1968 Turanophlebia Pritykina, 1968: 42 .

TYPE SPECIES. — Turanophlebia martynovi Pritykina, 1968 by monotypy.

OTHER SPECIES INCLUDED. — Turanophlebia sibirica Pritykina, 1977 , Turanophlebia anglicana n. sp., Turanophlebia mongolica n. sp., Turanophlebia vitimensis n. sp., Turanophlebia neckini ( Martynov, 1927) n. comb.

EMENDED DIAGNOSIS. — Differs from the Upper Jurassic Tarsophlebia eximia and Tarsophlebia minor n. sp. in its denser wing reticulation, mainly visible through: 1) the presence of more than 25 postnodal cross-veins (against 16 in T. eximia and around 11 in T. minor n. sp.); 2) six (or more) rows of cells between CuA and posterior hind wing margin (against less than five rows in T. eximia and T. minor n. sp.); 3) more than 10 secondary antenodal cross-veins in hind wing (against less than 10 in T. eximia ); 4) IR1 longer than in T. eximia ; and 5) presence of long secondary longitudinal not zigzagged veins in area between IR2 and RP2.

REMARKS

Jarzembowski (1990) considered that Tarsophlebia and Turanophlebia differ in: 1) general density of venation; 2) width of cubito-anal area; and 3) form of “discal cell” in hind wing (“pseudo-discoidal cell” sensu Nel et al. 1993). The shape of the “pseudo-discoidal” cell is variable in both Tarsophlebia eximia and the different species of Turanophlebia , thus the character 3) is not constant.

Figures

FIG. 2. — Tarsophlebia minor n. sp., holotype (No. 55, coll. Carpenter, MCZ), left hind wing. Scale bar: 10 mm.