Stenolestes rhodopensis, Nel, Simov, Bozukov & Marinov, 2016

Nel, A, Simov, N, Bozukov, V & Marinov, M, 2016, New dragonflies and damselflies from Middle Miocene deposits in SW Bulgaria (Insecta: Odonata), Palaeontologia Electronica 25 (2), pp. 1-13 : 5-7

Stenolestes rhodopensis sp. nov.

Figure 3

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Etymology. Named after the Rhodopes Mts. and mythical Thracian queen Rhodope.

Material. Holotype Сат-50a, Nr. Сат-50b (part and counterpart, Figure 3.1-4 ), paratype Сат-119 ( Figure 3.5 -6). Division of Palaeobotany and Palynology , Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria.

Diagnosis. Wing venation only. A large median dark zone on wing; only one row of cells between RP1 and IR1 basal of pterostigma. CuA moderately long, ending on posterior wing margin slightly distal of nodus level; ca. 32-34 postnodal crossveins; one row of cells below pterostigma between RA and RP1 ; base of RP2 nine cells distal of subnodus; only two intercalary rows of cells between RP1 and IR1 and three between IR1 and RP2 ; subnodus with inverted obliquity .

Description. Wing hyaline in basal and apical thirds but with a brown band in median third; wing 34.9 mm long, 7.9 mm wide; distance from base to arculus 3.9 mm; from arculus to nodus 7.7 mm, from nodus to pterostigma 15.6 mm, from pterostigma to wing apex 8.6 mm; nodus in a basal position; pterostigma long and broad, 4.2 mm long, 0.8 mm wide, covering five or six cells; pterostigmal brace absent; only three primary antenodal crossveins Ax0, Ax1 and Ax2 present, Ax2 aligned with arculus, distance between Ax1 and Ax2 ca. 2.3 mm; discoidal cell unicellular, 1.2 mm long and 1.2 mm wide, short and broad, broadened in its distal part, and with its distal side Mab not parallel with basal side, basal side of discoidal cell 0.45 mm long, anterior side 0.9 mm long, posterior side 1.2 mm long, MAb 1.2 mm long; ScP crossing through nodus, nodal crossvein Cr perpendicular to RA and subnodus Sn with a slight inverted obliquity; ca. 32-34 postnodal crossveins, not aligned with ca. 36 postsubnodal crossveins; bases of RP3/4 and IR2 between arculus and nodus, that of RP3/4 closer to arculus than to nodus, 2.5 mm distal of arculus, that of IR2 3.7 mm distal of arculus; base of RP2 nine cells and 3.7 mm distal of subnodus; base of IR1 four cells and 2.3 mm distally of that of RP2; oblique crossvein ‘O’ nine cells and 3.5 mm distal of base of RP2; vein CuP 0.4 mm distal of base of AA; cubito-anal area broad, with four rows of cells between CuA and posterior wing margin; CuA reaching posterior wing margin only 2.0 mm distal of nodus level; part of CuA basal of nodus level distinctly longer than part of CuA distal of nodus level; area between MP and posterior wing margin broad, with ca. eight rows of cells; postdiscoidal area narrow, 0.8 mm wide; area between MA and RP3/4 distally broadened; area between RP3/4 and IR2 distally broadened, with at least three rows of cells near posterior wing margin; IR2 slightly zigzagged in its distal fourth; three secondary longitudinal veins in area between IR2 and RP2; basal part of IR1 weakly zigzagged and distal part slightly curved; two secondary longitudinal veins in area between RP2 and IR1; two rows of cells in area between IR1 and RP1; one row of cells in area between RP1 and RA distal of pterostigma.

Discussion. Its shortly petiolated but large wings, ScP crossing through nodus, nodal Cr vertical and subnodus subvertical, bases of veins RP3/4 and IR2 midway between arculus and nodus, base of RP2 far from subnodus, show that this fossil is a sieblosiid. More precisely, this fossil can be attributed to the Sieblosiidae on the basis of the following synapomorphies ( Nel et al., 2005a): “angle between MAb and MP + CuA very open,” and “ScP crossing through nodus.” Following the phylogenetic analysis of Nel et al. (2005a), this fossil can be attributed to the clade ( Paraoligolestes Nel and Escuillié, 1993 + ( Parastenolestes Nel and Paicheler, 1994 + Stenolestes Scudder, 1895 )), supported by the synapomorphy “part of CuA distal of nodus level shorter than proximal part,” and to the clade ( Parastenolestes + Stenolestes ), supported by the character state “IR1 with a strong curve.” This last character is also present in Italolestes Nel et al., 2005b , but this last genus differs from our fossil in ScP not crossing through the nodus (see Nel et al., 2005 a, 2005b). Our fossil differs from the genus Germanostenolestes Nel and Fleck, 2012 (a genus close to Stenolestes and Parastenolestes ) in the presence of several rows of cells between RP3/4 and MA in the distal part of the wing ( Nel and Fleck, 2012). This fossil differs from Parastenolestes in the cells in the cubito-anal area not being transversely elongate ( Nel and Paicheler, 1994). It differs from the genus Sieblosia Handlirsch, 1906 (type species S. jucunda ( Hagen, 1858)) in the curved IR1, part of CuA distal of the nodus level being shorter than the proximal part, and discoidal cell short ( Nel et al., 2005a).

Within the genus Stenolestes , this fossil differs from S. adygeianensis Nel et al., 2005a in the different pattern of coloration of the wing (large apical dark zone in the latter taxon), presence of only one row of cells between RP1 and IR1 basal of the pterostigma in the former instead of two in the later. S. cerestensis Nel et al., 2005a has hyaline wings, short CuA reaching only the nodus level, and only 15 to 17 postnodal crossveins, unlike our fossil. S. fischeri Nel, 1986 has also a short CuA reaching only the nodus level. S. fasciata Nel et al., 2005a has a dark median area on its wing but in a more distal position than in our fossil, a CuA prolonged distinctly more distally than in our fossil, and two rows of cells below pterostigma. S. dauphinensis Nel et al., 1997 differs from our fossil in the base of RP2 being distinctly closer to the subnodus. S. belligaudi Nel et al., 1997 has hyaline wings, only 24 postnodal crossveins, and base of RP2 five cells distal of subnodus. S. andancensis Riou and Nel, 1995 , S. hispanicus Nel, 1991 , and S. camoinsi Nel, 1986 have 23 postnodal crossveins or less, unlike our fossil. S. ronzonensis ( Maneval, 1936) has many more intercalary veins and cells between main veins ( Nel and Paicheler, 1994). S. iris Scudder, 1895 has a straight RP2 and a broader area between RP2 and IR1 (with six rows of cells) than in our fossil ( Scudder, 1895). S. coulleti Nel and Papazian, 1986 has also a broader area between RP2 and IR1, with six rows of cells, plus base of RP2 only six cells distal of subnodus ( Nel and Papazian, 1986; Nel and Escuillié, 1992). S. falloti ( Théobald, 1937) differs from our fossil in the less numerous postnodal crossveins (ca. 28 instead of more than 30), vertical subnodus, and CuA ending much more distal to nodus level than in our fossil (Nel, 1986). As this fossil differs from all the other species in the genus Stenolestes , we consider that it belongs to a new species.

Figures

FIGURE 3. Stenolestes rhodopensis sp. nov. 1, holotype Caт-50a (part); 2, holotype Caт-50b (part); 3, 4, Сат-50a and Сат-50b – both wings; 5, paratype Caт-119 (whole insect); 6, paratype Caт-119 (wings only). Scale bars represent 5 mm in 1, 2, 3, 4, 6; 1 cm in 5.

FIGURE 4. Primorilestes magnificus sp. nov. 1, holotype Сат-52 (part); 2, holotype Caт-53 (part); 3, paratype Caт-54. Scale bars represent 5 mm in all figures.