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A new damsel-dragonfly from the Lower Cretaceous of China enlightens the systematics of the Isophlebioidea (Odonata: Isophlebioptera: Campterophlebiidae)
Cretaceous Research 34 (2012) 340e343
Contents lists available at SciVerse ScienceDirect
Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes
A new damsel-dragonfly from the Lower Cretaceous of China enlightens the systematics of the Isophlebioidea (Odonata: Isophlebioptera: Campterophlebiidae) Yongjun Li a, André Nel b, *, Dong Ren c, Hong Pang a a b c
State Key Laboratory of Biocontrol and Institute of Entomology, Sun Yat-Sen University, Guangzhou 510275, China CNRS UMR 7205, CP 50, Entomologie, Muséum National d’Histoire Naturelle, 45 rue Buffon, F-75005 Paris, France College of Life Sciences, Capital Normal University, Beijing 100037, China
a r t i c l e i n f o
a b s t r a c t
Article history: Received 30 November 2010 Accepted in revised form 29 November 2011 Available online 6 December 2011
A new genus and species of isophlebioid, Parafleckium senjituense, is described from the Lower Cretaceous Yixian Formation in China. As it has several significant structures currently considered as typical of either the Campterophlebiidae or the Isophlebiidae, and it helps to clarify knowledge of the morphology and taxonomy of this group of damsel-dragonflies. We propose an emendation of the diagnoses of these two families. Ó 2011 Elsevier Ltd. All rights reserved.
Keywords: Fossil insects Early Cretaceous Isophlebiidea Emended family diagnoses
1. Introduction
2. Material and method
The Isophlebioptera Bechly, 1996 is an insect clade that flourished during the Triassic, Jurassic and Early Cretaceous in Europe and Central Asia (Fleck and Nel, 2002). More than 50 species have been described (Bechly, 1996; Nel et al., 1993, 2007, 2008), many of which are based on isolated and sometimes fragmentary wings. Zhang et al. (2008) concisely revised the Campterophlebiidae Handlirsch, 1920, which is the largest damsel-dragonfly family. Nel et al. (2009) emended the diagnoses of the Campterophlebiidae and Isophlebiidae Handlirsch, 1906. However, because of the shortage of material, especially in a wellpreserved state, the clade Isophlebioptera is still poorly known and a phylogenetic study of the superfamily Isophlebioidea Handlirsch, 1906 is needed. In this paper, we described a new genus and species, Parafleckium senjituense. This fossil shows some important characters proposed by Nel et al. (2009) for both the Campterophlebiidae and the Isophlebiidae, so it is of interest for clarifying the limits and definitions of these families.
The study is based on a single specimen (CNU-ODO-LB2010002; Fig. 1) housed in the Key Laboratory of Insect Evolution and Environmental Changes, Capital Normal University, Beijing, China. The specimen was examined under a Leica MZ12.5 dissecting microscope and illustrated with the aid of a drawing tube attached to it. Line drawings were made using Adobe Photoshop CS graphic software. The wing venation nomenclature used follows Riek (1976) and Riek and Kukalová-Peck (1984), as amended by Nel et al. (1993) and Bechly (1996). We use the following standard abbreviations: AA, anal anterior; AP, anal posterior; Ax0 Ax1 Ax2, primary antenodal cross-veins; CuAa, distal branch of cubitus anterior; CuAb, proximal branch of cubitus anterior; IR1, IR2, intercalary radial veins; MAa, distal branch of median anterior; MAb, posterior branch of median anterior; MP, median posterior; N, nodus; “O”, oblique vein; Pt, pterostigma; RA, radius anterior; RP, radius posterior; Su.C, subdiscoidal cell; D.C., discoidal cell.
* Corresponding author. E-mail addresses: [email protected] (Y. Li), [email protected] (A. Nel), [email protected] (D. Ren). 0195-6671/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.cretres.2011.11.019
3. Systematic palaeontology Order Odonata Fabricius, 1793 Clade Isophlebioptera Bechly, 1996 Superfamily Isophlebioidea Handlirsch, 1906 Family Campterophlebiidae Handlirsch, 1920
Y. Li et al. / Cretaceous Research 34 (2012) 340e343
Genus Parafleckium gen. nov. Type species. Parafleckium senjituense gen. and sp. nov. Derivation of name. After Amnifleckia, because of its similarities to this genus (hence “para”). Gender uncertain. Diagnosis. Forewing characters only. Gaff (basal part of CuA) straight and very long, correlated with proximal part of area between MP and CuA, about three times as wide as proximal part of area between MA and MP; Ax1 basal of arculus, very oblique; Ax2 almost perpendicular to ScP and RA, in a rather distal position, nearly mid-way between wing base and nodus; a secondary longitudinal vein in anal area parallel to AA and posterior wing margin; a long single cell covering the whole area between MP and CuA, just distal of gaff; areas between MAa and MP and between IR2 and RP3/4 greatly broadened in their mid parts and distinctly constricted near wing margin; MP and RP3/4 curved in mid part;
341
CuAa very short; numerous cells below narrow pterostigma; IR2 originating from RP3/4; oblique vein “O” very oblique and strong, only seven cells distal of base of RP2. Parafleckium senjituense sp. nov. Figs. 1e3 Derivation of name. After Senjitu Township where the fossil was found. Material. A single specimen (holotype), as noted above. Formation, age and location. Yixian Formation, Aptian (e.g. Sun et al., 2011); Xituyao Village, Senjitu Township, Fengning County, Hebei Province, Northeast China. Description. Fossil incomplete with only two forewings and a small part of thorax preserved; right forewing with apex missing and
Fig. 1. Photograph of holotype of Parafleckium senjituense gen. et sp. nov. Scale bar represents 10 mm.
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Y. Li et al. / Cretaceous Research 34 (2012) 340e343
Fig. 2. Line drawing of right forewing of Parafleckium senjituense gen. et sp. nov. Scale bar represents 10 mm.
only main veins visible in mid part; left forewing folded near base. However, the nearly complete wing venation can be reconstructed by combining information from the two wings. The main directions of these wings are nearly at right angles. The left wing is clearly diagenetically distorted and elongate, the deformation affecting the right wing is less important. Nevertheless, we give the main dimensions for both of them. Fortunately the diagnostic characters of the species are not affected by the deformation. Wings hyaline, not petiolate; pterostigma dark brown; forewing 83.2 mm long (left), 70.0 mm long (right), 20.1 mm wide (left), 20.0 mm long (right); distance between base and arculus 7.8 mm (left), 7.8 mm (right), between arculus and nodus 25.2 mm (left), 26.0 mm (right); distance from nodus to base of pterostigma 18.9 mm (left), 19.0 mm (right); distance between Ax1 and Ax2 10.3 mm (left), 10.0 mm (right), between Ax1 and wing base 6.5 mm (left), 6.3 mm (right), between Ax2 and nodus 18.0 mm (left), 17.7 mm (right); Ax1 1.1 mm basal of arculus (left), 1.3 mm (right); Ax1 very oblique and Ax2 nearly perpendicular to ScP; pterostigma (distal part missing in right forewing and not clear in left forewing) elongated and narrow, sclerotized, perhaps 0.9 mm wide and 8.9 mm long, numerous cells below it, rather distinctly basally recessed for presence of numerous cells between C and RA distal of it; no pterostigmal brace; veins C and RA not widened along pterostigma; median and submedian spaces free of crossveins; discoidal space basally opened; subdiscoidal cell free of cross-veins, large and broad, rectangular transverse, 3.1 mm long and 1.5 mm wide at mid part (left), 3.5 mm and 2.0 mm (right); a long single cell covering whole area between MP and CuA, just distal of gaff; AA distally strongly bent towards posterior wing margin at CuP, crossing and more or less parallel to CuA, then distally fused with a secondary longitudinal vein into a strong vein
parallel to posterior wing margin and distally reaching CuA; anal area with two rows of large cells and a strong longitudinal secondary vein; gaff (basal part of CuA before its furcation) very elongated, 3.9 mm long (left), 3.7 mm (right), basal part of area between MP and CuA 4.0 mm wide (left), 4.1 mm (right), about three times as broad as basal part of post-discoidal area between MA and MP, 1.2 mm wide (left), 1.3 mm (right); CuAa parallel to posterior wing margin for a short distance (about 9.8 mm long in left wing), then weakened and fused with posterior wing margin, with one row of longitudinal cells below CuA; CuAb very short and directed towards posterior wing margin; area between CuA and MP with 2e3 rows of large cells basally and greatly broadened distally with 6e8 rows of irregular cells; MP strongly undulating at mid part; MA very slightly curved and slightly zigzagged distally; one row of cells in post-discoidal area, greatly constricted near wing margin; base of RP3/4 8.8 mm distal of arculus and 16.3 mm basal of nodus; vein CP bent towards ScP but not reaching it in nodus, with a small empty space between the two veins; subnodus weakly oblique; RP2 not aligned, 0.6 mm basal to subnodus; one oblique; a distinct oblique vein “O”, seven cells and 5.8 mm distal of base of RP2 in left wing; RP2 slightly undulating distally; area between IR2 and RP2 with one row of cells from their bases to level of pterostigma, distally widened with about 5e6 rows of cells near posterior wing margin; in left forewing, IR1 apparently bifurcates distally; IR1 slightly curved, basally smoothly zigzagged but distally nearly straight, more or less parallel to RP1; base of IR1 7.6 mm distal of base of RP2 in left wing; area between MA and RP3/4 strongly widened distally, with more than 14 rows of cells along posterior wing margin, but basally parallel with one row of cells between them; IR2 with apparent origin on RP3/4; area between RP3/4 and IR2 greatly widened in mid part but distally constricted,
Fig. 3. Line drawing of left forewing of Parafleckium senjituense gen. et sp. nov. Scale bar represents 10 mm.
Y. Li et al. / Cretaceous Research 34 (2012) 340e343
with four rows of cells at its widest part; a secondary longitudinal vein (“Rspl”) parallel to IR2 and one row of cells between them, and the area between is constricted; area between RP2 and IR1 progressively widened, with about nine rows of cells along posterior wing margin; a very strong oblique vein between IR1 and RP2, 7.0 mm distal of base of IR1. 4. Discussion Parafleckium senjituense gen. and sp. nov. shows some similarities with Bellabrunetia catherinae Fleck and Nel, 2002, Amnifleckia guttata Zhang et al., 2006 and Parabrunetia celinea Huang et al., 2006 (in Zhang et al., 2006), namely a very short CuAa, a constricted area between IR2 and RP3/4, a long and straight gaff, and a similar pattern of the main longitudinal veins. Furthermore, its vein IR2 originates from RP3/4 as in A. guttata and P. celinea (Fleck and Nel, 2002; Zhang et al., 2006). The main differences from the three taxa above are: (1) the Ax1 is oblique and Ax2 is nearly perpendicular to ScP and RA; (2) Ax2 is in a very distal position; (3) the pterostigma is much more prolonged, covering numerous cells; (4) RP2 is not aligned with nodus; (5) the base of IR2 is not very close to the base of RP3/4; (6) RP3/4 is much more undulating, and the area between IR2 and RP3/4 much more expanded; (7) there is a very welldeveloped secondary longitudinal vein “Rspl”; (8) MP is strongly undulating in its mid part; (9) the gaff is very long and, correlated with the basal area between MP and CuA, is more than three times as wide as the post-discoidal area; (10) the forewing is distinctly broader. Parafleckium senjituense can be attributed to the Campterophlebiidae on the basis of some of the diagnostic characters proposed by Nel et al. (2009), namely: the forewing discoidal cell is basally open and correlated with the absence of any shifting of the distal side (MAb) of the discoidal cell distinctly distal of the arculus, and there are no secondary antenodal cross-veins between C and ScP. Nevertheless it has also some characters of the Isophlebiidae (Nel et al., 2009): Ax1 oblique, gaff further prolonged, and RP3/4 not parallel to IR2. Thus on the basis of the present study, it is necessary to emend the diagnosis proposed by Nel et al. (2009) for the Campterophlebiidae, by removing the plesiomorphic character “area between MP and CuA less than twice as wide as post-discoidal area in their basal parts”. Indeed Parafleckium has a very broad area between MP and CuA. This apomorphic state is also present in some Isophlebiidae, such as Dahurium draco Pritykina, 2006, in which the basal part of the area between MP and CuA (2.1 mm wide in forewing and 2.3 mm in hindwing) is less than twice as wide as the basal part of the post-discoidal area (1.5 mm wide in forewing and 3.9 mm wide in hindwing; Pritykina, 2006).
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We can also emend the diagnosis of the Isophlebiidae, by removing two characters: “Ax1 and Ax2 of distinct and converging obliquity, especially owing to the strong obliquity of Ax1”, because it can be seen in the campterophlebiid Sinitsia sophiae Pritykina, 2006; and “RP3/4 not parallel to IR2”, which is very variable. Parafleckium senjituense shows that the definition and limits of the two families Isophlebiidae and Campterophlebiidae are still not very clear and in need of a phylogenetic analysis. It also confirms that this group of damsel-dragonflies was very diverse in China during the Early Cretaceous (Nel et al., 2008; Zhang et al., 2008). Acknowledgements This research was supported by the National Natural Science Foundation of China (Nos. 40872022, 30811120038, 31071964), the Nature Science Foundation of Beijing (No. 5082002) and Scientific Research Key Program KZ200910028005 and PHR Project of Beijing Municipal Commission of Education. References Bechly, G., 1996. Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata. Petalura, Special Volume 2, 402. Fleck, G., Nel, A., 2002. The first isophlebioid dragonfly (Odonata: Isophlebioptera: Campterophlebiidae) from the Mesozoic of China. Palaeontology 45, 1123e1136. Nel, A., Bechly, G., Delclòs, X., Huang, D.Y., 2009. New and poorly known Mesozoic damsel-dragonflies (Odonata: Isophlebioidea: Campterophlebiidae, Isophlebiidae). Palaeodiversity 2, 209e232. Nel, A., Huang, D.Y., Lin, Q.B., 2007. A new genus of isophlebioid damsel-dragonflies (Odonata: Isophlebioptera: Campterophlebiidae) from the Middle Jurassic of China. Zootaxa 1642, 13e22. Nel, A., Huang, D.Y., Lin, Q.B., 2008. A new genus of isophlebioid damsel-dragonflies with “calopterygid”-like wing shape from the Middle Jurassic of China (Odonata: Isophlebioidea: Campterophlebiidae). European Journal of Entomology 105, 783e787. Nel, A., Martínez-Delclòs, X., Paicheler, J.-C., Henrotay, M., 1993. Les ‘Anisozygoptera’ fossiles. Phylogénie et classification (Odonata). Martinia Hors Série 3, 1e311. Pritykina, L.N., 2006. Isophlebiid dragonflies from the late Mesozoic of eastern Transbaikalia (Odonata: Isophlebiidae). Paleontological Journal 40, 636e645. Riek, E.F., 1976. A new collection of insects from the Upper Triassic of South Africa. Annals of the Natal Museum 22, 791e820. Riek, E.F., Kukalová-Peck, J., 1984. A new interpretation of dragonfly wing venation based upon Early Carboniferous fossils from Argentina (Insecta: Odonatoidea) and basic characters states in pterygote wings. Canadian Journal of Zoology 62, 1150e1166. Sun, G., Dilcher, D.L., Wang, H.S., Chen, Z.D., 2011. A eudicot from the Early Cretaceous of China. Nature 471, 625e628. Zhang, B.L., Fleck, G., Huang, D.Y., Nel, A., Ren, D., Cheng, X.D., Lin, Q.B., 2006. New isophlebioid dragonflies (Odonata: Isophlebioptera: Campterophlebiidae) from the Middle Jurassic of China. Zootaxa 1339, 51e68. Zhang, B.L., Ren, D., Pang, H., 2008. New isophlebioid dragonflies from the Middle Jurassic of Inner Mongolia, China (Insecta: Odonata: Isophlebioptera: Campterophlebiidae). Acta Geologica Sinica (English Edition) 82, 1104e1114.
Contents lists available at SciVerse ScienceDirect
Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes
A new damsel-dragonfly from the Lower Cretaceous of China enlightens the systematics of the Isophlebioidea (Odonata: Isophlebioptera: Campterophlebiidae) Yongjun Li a, André Nel b, *, Dong Ren c, Hong Pang a a b c
State Key Laboratory of Biocontrol and Institute of Entomology, Sun Yat-Sen University, Guangzhou 510275, China CNRS UMR 7205, CP 50, Entomologie, Muséum National d’Histoire Naturelle, 45 rue Buffon, F-75005 Paris, France College of Life Sciences, Capital Normal University, Beijing 100037, China
a r t i c l e i n f o
a b s t r a c t
Article history: Received 30 November 2010 Accepted in revised form 29 November 2011 Available online 6 December 2011
A new genus and species of isophlebioid, Parafleckium senjituense, is described from the Lower Cretaceous Yixian Formation in China. As it has several significant structures currently considered as typical of either the Campterophlebiidae or the Isophlebiidae, and it helps to clarify knowledge of the morphology and taxonomy of this group of damsel-dragonflies. We propose an emendation of the diagnoses of these two families. Ó 2011 Elsevier Ltd. All rights reserved.
Keywords: Fossil insects Early Cretaceous Isophlebiidea Emended family diagnoses
1. Introduction
2. Material and method
The Isophlebioptera Bechly, 1996 is an insect clade that flourished during the Triassic, Jurassic and Early Cretaceous in Europe and Central Asia (Fleck and Nel, 2002). More than 50 species have been described (Bechly, 1996; Nel et al., 1993, 2007, 2008), many of which are based on isolated and sometimes fragmentary wings. Zhang et al. (2008) concisely revised the Campterophlebiidae Handlirsch, 1920, which is the largest damsel-dragonfly family. Nel et al. (2009) emended the diagnoses of the Campterophlebiidae and Isophlebiidae Handlirsch, 1906. However, because of the shortage of material, especially in a wellpreserved state, the clade Isophlebioptera is still poorly known and a phylogenetic study of the superfamily Isophlebioidea Handlirsch, 1906 is needed. In this paper, we described a new genus and species, Parafleckium senjituense. This fossil shows some important characters proposed by Nel et al. (2009) for both the Campterophlebiidae and the Isophlebiidae, so it is of interest for clarifying the limits and definitions of these families.
The study is based on a single specimen (CNU-ODO-LB2010002; Fig. 1) housed in the Key Laboratory of Insect Evolution and Environmental Changes, Capital Normal University, Beijing, China. The specimen was examined under a Leica MZ12.5 dissecting microscope and illustrated with the aid of a drawing tube attached to it. Line drawings were made using Adobe Photoshop CS graphic software. The wing venation nomenclature used follows Riek (1976) and Riek and Kukalová-Peck (1984), as amended by Nel et al. (1993) and Bechly (1996). We use the following standard abbreviations: AA, anal anterior; AP, anal posterior; Ax0 Ax1 Ax2, primary antenodal cross-veins; CuAa, distal branch of cubitus anterior; CuAb, proximal branch of cubitus anterior; IR1, IR2, intercalary radial veins; MAa, distal branch of median anterior; MAb, posterior branch of median anterior; MP, median posterior; N, nodus; “O”, oblique vein; Pt, pterostigma; RA, radius anterior; RP, radius posterior; Su.C, subdiscoidal cell; D.C., discoidal cell.
* Corresponding author. E-mail addresses: [email protected] (Y. Li), [email protected] (A. Nel), [email protected] (D. Ren). 0195-6671/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.cretres.2011.11.019
3. Systematic palaeontology Order Odonata Fabricius, 1793 Clade Isophlebioptera Bechly, 1996 Superfamily Isophlebioidea Handlirsch, 1906 Family Campterophlebiidae Handlirsch, 1920
Y. Li et al. / Cretaceous Research 34 (2012) 340e343
Genus Parafleckium gen. nov. Type species. Parafleckium senjituense gen. and sp. nov. Derivation of name. After Amnifleckia, because of its similarities to this genus (hence “para”). Gender uncertain. Diagnosis. Forewing characters only. Gaff (basal part of CuA) straight and very long, correlated with proximal part of area between MP and CuA, about three times as wide as proximal part of area between MA and MP; Ax1 basal of arculus, very oblique; Ax2 almost perpendicular to ScP and RA, in a rather distal position, nearly mid-way between wing base and nodus; a secondary longitudinal vein in anal area parallel to AA and posterior wing margin; a long single cell covering the whole area between MP and CuA, just distal of gaff; areas between MAa and MP and between IR2 and RP3/4 greatly broadened in their mid parts and distinctly constricted near wing margin; MP and RP3/4 curved in mid part;
341
CuAa very short; numerous cells below narrow pterostigma; IR2 originating from RP3/4; oblique vein “O” very oblique and strong, only seven cells distal of base of RP2. Parafleckium senjituense sp. nov. Figs. 1e3 Derivation of name. After Senjitu Township where the fossil was found. Material. A single specimen (holotype), as noted above. Formation, age and location. Yixian Formation, Aptian (e.g. Sun et al., 2011); Xituyao Village, Senjitu Township, Fengning County, Hebei Province, Northeast China. Description. Fossil incomplete with only two forewings and a small part of thorax preserved; right forewing with apex missing and
Fig. 1. Photograph of holotype of Parafleckium senjituense gen. et sp. nov. Scale bar represents 10 mm.
342
Y. Li et al. / Cretaceous Research 34 (2012) 340e343
Fig. 2. Line drawing of right forewing of Parafleckium senjituense gen. et sp. nov. Scale bar represents 10 mm.
only main veins visible in mid part; left forewing folded near base. However, the nearly complete wing venation can be reconstructed by combining information from the two wings. The main directions of these wings are nearly at right angles. The left wing is clearly diagenetically distorted and elongate, the deformation affecting the right wing is less important. Nevertheless, we give the main dimensions for both of them. Fortunately the diagnostic characters of the species are not affected by the deformation. Wings hyaline, not petiolate; pterostigma dark brown; forewing 83.2 mm long (left), 70.0 mm long (right), 20.1 mm wide (left), 20.0 mm long (right); distance between base and arculus 7.8 mm (left), 7.8 mm (right), between arculus and nodus 25.2 mm (left), 26.0 mm (right); distance from nodus to base of pterostigma 18.9 mm (left), 19.0 mm (right); distance between Ax1 and Ax2 10.3 mm (left), 10.0 mm (right), between Ax1 and wing base 6.5 mm (left), 6.3 mm (right), between Ax2 and nodus 18.0 mm (left), 17.7 mm (right); Ax1 1.1 mm basal of arculus (left), 1.3 mm (right); Ax1 very oblique and Ax2 nearly perpendicular to ScP; pterostigma (distal part missing in right forewing and not clear in left forewing) elongated and narrow, sclerotized, perhaps 0.9 mm wide and 8.9 mm long, numerous cells below it, rather distinctly basally recessed for presence of numerous cells between C and RA distal of it; no pterostigmal brace; veins C and RA not widened along pterostigma; median and submedian spaces free of crossveins; discoidal space basally opened; subdiscoidal cell free of cross-veins, large and broad, rectangular transverse, 3.1 mm long and 1.5 mm wide at mid part (left), 3.5 mm and 2.0 mm (right); a long single cell covering whole area between MP and CuA, just distal of gaff; AA distally strongly bent towards posterior wing margin at CuP, crossing and more or less parallel to CuA, then distally fused with a secondary longitudinal vein into a strong vein
parallel to posterior wing margin and distally reaching CuA; anal area with two rows of large cells and a strong longitudinal secondary vein; gaff (basal part of CuA before its furcation) very elongated, 3.9 mm long (left), 3.7 mm (right), basal part of area between MP and CuA 4.0 mm wide (left), 4.1 mm (right), about three times as broad as basal part of post-discoidal area between MA and MP, 1.2 mm wide (left), 1.3 mm (right); CuAa parallel to posterior wing margin for a short distance (about 9.8 mm long in left wing), then weakened and fused with posterior wing margin, with one row of longitudinal cells below CuA; CuAb very short and directed towards posterior wing margin; area between CuA and MP with 2e3 rows of large cells basally and greatly broadened distally with 6e8 rows of irregular cells; MP strongly undulating at mid part; MA very slightly curved and slightly zigzagged distally; one row of cells in post-discoidal area, greatly constricted near wing margin; base of RP3/4 8.8 mm distal of arculus and 16.3 mm basal of nodus; vein CP bent towards ScP but not reaching it in nodus, with a small empty space between the two veins; subnodus weakly oblique; RP2 not aligned, 0.6 mm basal to subnodus; one oblique; a distinct oblique vein “O”, seven cells and 5.8 mm distal of base of RP2 in left wing; RP2 slightly undulating distally; area between IR2 and RP2 with one row of cells from their bases to level of pterostigma, distally widened with about 5e6 rows of cells near posterior wing margin; in left forewing, IR1 apparently bifurcates distally; IR1 slightly curved, basally smoothly zigzagged but distally nearly straight, more or less parallel to RP1; base of IR1 7.6 mm distal of base of RP2 in left wing; area between MA and RP3/4 strongly widened distally, with more than 14 rows of cells along posterior wing margin, but basally parallel with one row of cells between them; IR2 with apparent origin on RP3/4; area between RP3/4 and IR2 greatly widened in mid part but distally constricted,
Fig. 3. Line drawing of left forewing of Parafleckium senjituense gen. et sp. nov. Scale bar represents 10 mm.
Y. Li et al. / Cretaceous Research 34 (2012) 340e343
with four rows of cells at its widest part; a secondary longitudinal vein (“Rspl”) parallel to IR2 and one row of cells between them, and the area between is constricted; area between RP2 and IR1 progressively widened, with about nine rows of cells along posterior wing margin; a very strong oblique vein between IR1 and RP2, 7.0 mm distal of base of IR1. 4. Discussion Parafleckium senjituense gen. and sp. nov. shows some similarities with Bellabrunetia catherinae Fleck and Nel, 2002, Amnifleckia guttata Zhang et al., 2006 and Parabrunetia celinea Huang et al., 2006 (in Zhang et al., 2006), namely a very short CuAa, a constricted area between IR2 and RP3/4, a long and straight gaff, and a similar pattern of the main longitudinal veins. Furthermore, its vein IR2 originates from RP3/4 as in A. guttata and P. celinea (Fleck and Nel, 2002; Zhang et al., 2006). The main differences from the three taxa above are: (1) the Ax1 is oblique and Ax2 is nearly perpendicular to ScP and RA; (2) Ax2 is in a very distal position; (3) the pterostigma is much more prolonged, covering numerous cells; (4) RP2 is not aligned with nodus; (5) the base of IR2 is not very close to the base of RP3/4; (6) RP3/4 is much more undulating, and the area between IR2 and RP3/4 much more expanded; (7) there is a very welldeveloped secondary longitudinal vein “Rspl”; (8) MP is strongly undulating in its mid part; (9) the gaff is very long and, correlated with the basal area between MP and CuA, is more than three times as wide as the post-discoidal area; (10) the forewing is distinctly broader. Parafleckium senjituense can be attributed to the Campterophlebiidae on the basis of some of the diagnostic characters proposed by Nel et al. (2009), namely: the forewing discoidal cell is basally open and correlated with the absence of any shifting of the distal side (MAb) of the discoidal cell distinctly distal of the arculus, and there are no secondary antenodal cross-veins between C and ScP. Nevertheless it has also some characters of the Isophlebiidae (Nel et al., 2009): Ax1 oblique, gaff further prolonged, and RP3/4 not parallel to IR2. Thus on the basis of the present study, it is necessary to emend the diagnosis proposed by Nel et al. (2009) for the Campterophlebiidae, by removing the plesiomorphic character “area between MP and CuA less than twice as wide as post-discoidal area in their basal parts”. Indeed Parafleckium has a very broad area between MP and CuA. This apomorphic state is also present in some Isophlebiidae, such as Dahurium draco Pritykina, 2006, in which the basal part of the area between MP and CuA (2.1 mm wide in forewing and 2.3 mm in hindwing) is less than twice as wide as the basal part of the post-discoidal area (1.5 mm wide in forewing and 3.9 mm wide in hindwing; Pritykina, 2006).
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We can also emend the diagnosis of the Isophlebiidae, by removing two characters: “Ax1 and Ax2 of distinct and converging obliquity, especially owing to the strong obliquity of Ax1”, because it can be seen in the campterophlebiid Sinitsia sophiae Pritykina, 2006; and “RP3/4 not parallel to IR2”, which is very variable. Parafleckium senjituense shows that the definition and limits of the two families Isophlebiidae and Campterophlebiidae are still not very clear and in need of a phylogenetic analysis. It also confirms that this group of damsel-dragonflies was very diverse in China during the Early Cretaceous (Nel et al., 2008; Zhang et al., 2008). Acknowledgements This research was supported by the National Natural Science Foundation of China (Nos. 40872022, 30811120038, 31071964), the Nature Science Foundation of Beijing (No. 5082002) and Scientific Research Key Program KZ200910028005 and PHR Project of Beijing Municipal Commission of Education. References Bechly, G., 1996. Morphologische Untersuchungen am Flügelgeäder der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata), unter besonderer Berücksichtigung der Phylogenetischen Systematik und des Grundplanes der Odonata. Petalura, Special Volume 2, 402. Fleck, G., Nel, A., 2002. The first isophlebioid dragonfly (Odonata: Isophlebioptera: Campterophlebiidae) from the Mesozoic of China. Palaeontology 45, 1123e1136. Nel, A., Bechly, G., Delclòs, X., Huang, D.Y., 2009. New and poorly known Mesozoic damsel-dragonflies (Odonata: Isophlebioidea: Campterophlebiidae, Isophlebiidae). Palaeodiversity 2, 209e232. Nel, A., Huang, D.Y., Lin, Q.B., 2007. A new genus of isophlebioid damsel-dragonflies (Odonata: Isophlebioptera: Campterophlebiidae) from the Middle Jurassic of China. Zootaxa 1642, 13e22. Nel, A., Huang, D.Y., Lin, Q.B., 2008. A new genus of isophlebioid damsel-dragonflies with “calopterygid”-like wing shape from the Middle Jurassic of China (Odonata: Isophlebioidea: Campterophlebiidae). European Journal of Entomology 105, 783e787. Nel, A., Martínez-Delclòs, X., Paicheler, J.-C., Henrotay, M., 1993. Les ‘Anisozygoptera’ fossiles. Phylogénie et classification (Odonata). Martinia Hors Série 3, 1e311. Pritykina, L.N., 2006. Isophlebiid dragonflies from the late Mesozoic of eastern Transbaikalia (Odonata: Isophlebiidae). Paleontological Journal 40, 636e645. Riek, E.F., 1976. A new collection of insects from the Upper Triassic of South Africa. Annals of the Natal Museum 22, 791e820. Riek, E.F., Kukalová-Peck, J., 1984. A new interpretation of dragonfly wing venation based upon Early Carboniferous fossils from Argentina (Insecta: Odonatoidea) and basic characters states in pterygote wings. Canadian Journal of Zoology 62, 1150e1166. Sun, G., Dilcher, D.L., Wang, H.S., Chen, Z.D., 2011. A eudicot from the Early Cretaceous of China. Nature 471, 625e628. Zhang, B.L., Fleck, G., Huang, D.Y., Nel, A., Ren, D., Cheng, X.D., Lin, Q.B., 2006. New isophlebioid dragonflies (Odonata: Isophlebioptera: Campterophlebiidae) from the Middle Jurassic of China. Zootaxa 1339, 51e68. Zhang, B.L., Ren, D., Pang, H., 2008. New isophlebioid dragonflies from the Middle Jurassic of Inner Mongolia, China (Insecta: Odonata: Isophlebioptera: Campterophlebiidae). Acta Geologica Sinica (English Edition) 82, 1104e1114.