Sinoagetopanorpidae fam. nov., a New Family of Scorpionflies (Insecta, Mecoptera) from the Guadalupian of South China

Simple Summary

Mecopterans have been sparsely reported from the Permian of China, despite their great biodiversity in the fossil record in the world. Herein, we describe and illustrate three genera (two new genera) and eleven species (ten new species) belonging to a new family Sinoagetopanorpidae fam. nov. from the upper Guadalupian Yinping Formation of Anhui Province, China: Sinoagetopanorpa permiana Lin, Nel and Huang, 2010, S. nigra sp. nov., S. rotunda sp. nov., S. lini sp. nov., S. minuta sp. nov., S. elegans sp. nov., S. grimaldii sp. nov., S. magna sp. nov., Raragetopanorpa zhangi gen. et sp. nov., Permoagetopanorpa yinpingensis gen. et sp. nov. and P. incompleta sp. nov. Our new discovery indicates a high diversity of mecopterans in the Permian of China, and Signoagetopanorpidae might have evolved independently on the Yangtze Platform.

Abstract

Mecoptera was in great abundance in the Permian, but little is known from China. A new family, Sinoagetopanorpidae fam. nov., is described and illustrated from the upper Guadalupian Yinping Formation at Yinping Mountain, Chaohu City, Anhui Province, China. Sinoagetopaorpa permiana Lin, Nel and Huang, 2010 was previously attributed to Permochoristidae and now is revised as the type species of Sinoagetopanorpidae fam. nov. Three genera (two new genera) and ten new species of this new family are described and illustrated: Sinoagetopanorpa permiana Lin, Nel and Huang, 2010, S. nigra sp. nov., S. rotunda sp. nov., S. lini sp. nov., S. minuta sp. nov., S. elegans sp. nov., S. grimaldii sp. nov., S. magna sp. nov., Raragetopanorpa zhangi gen. et sp. nov., Permoagetopanorpa yinpingensis gen. et sp. nov. and P. incompleta sp. nov. Some isolated hind wings are described and illustrated, although it is difficult to assign them to any particular species. As a dominant mecopteran lineage in the Yinping Formation, Sinoagetopanorpidae represents an endemic group that might have independently evolved on the Yangtze Platform.

1. Introduction

The common name “scorpionflies” of the insect order Mecoptera is derived from the fact that some males bear unturned and bulbous genitalia that resemble the stingers of scorpions. Holometabolous insects have the richest biodiversity among all insect clades and can be dated back to the Pennsylvanian [1]. Mecoptera is one of the most ancient and morphologically generalized holometabolous insect orders, and they represent an important holometabolous group in the Permian. Mecoptera can be traced back to the beginning of the Permian [2] and thrived from the Permian to Cretaceous [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]. However, many mecopteran lineages went extinct during the Cretaceous, and a modern-looking mecopteran assemblage emerged in the Cenozoic. Extant mecopterans encompass ca. 700 species and 40 genera assigned to 9 families [21,22]. Bittacidae and Panorpidae are overwhelmingly diverse among mecopterans in the extant fauna. Mecoptera is more prosperous in the fossil record than it is in the Recent, with more than 700 species and 210 genera in approximately 40 families recorded to date [22,23,24].

Mecopterans were abundant and since the Cisuralian; more than 200 species and 40 genera of Permian mecopterans have been described from Africa, the Americas, Asia, Australia, Europe and India [5,6,25,26,27,28,29,30,31]. Rare specimens of Permian mecopterans in China were described from the Yinping Formation [31,32,33], represented by three reported species: Sinoagetopanorpa permiana Lin, Nel and Huang, 2010, Permica chaohuensis Lian, Cai and Huang, 2022 and Chaohuchorista liaoi Lian, Cai and Huang, 2022. Sinoagetopanorpa permiana is peculiar in its broad wing and costal area, and the apically curved R₁. Lin et al. [31] assigned S. permiana to Permochoristidae Tillyard, 1917 originally. However, the holotype of S. permiana is slightly deformed, and the line drawings were probably not precise in the original paper. During the past 12 years, we have collected 56 specimens closely related to S. permiana from the same fossil layer. Some are exquisitely preserved with details of dark color and body structures. Here, we provide a systematic classification based on new specimens and establish a new mecopteran family.

2. Materials and Methods

All specimens were collected from black shales of the lower part of the Yinping Formation near Houdong Village, Sanbing Township, Chaohu City, Anhui Province, China (Figure 1). The Yinping Formation is of the late Capitanian in age [34,35] and it has yielded rich fossils, including sponges, marine bivalves, insects, shrimps, fishes and plants. Fossil insects are diverse, including Orthoptera, Coleoptera, Glosselytrodea, Mecoptera, Hemiptera, Caloneurodea and Megasecoptera [31,36,37,38,39,40,41,42].

The specimens were carefully prepared using a sharp knife. Photographs were taken by a digital camera attached to a Zeiss Discovery V20 microscope (Carl Zeiss AG, Oberkochen, Germany). Most specimens are displayed in two pictures; one was taken in vertical reflected light and immersed under 70% alcohol to improve the contrast of dark color, and the other one was taken in oblique reflected light for displaying veins. Line drawings and maps were made using Adobe Illustrator 2019 graphic software. The specimens are housed in the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China.

The wing venation nomenclature generally follows the scheme of Minet et al. [43] and partly follows Bashkuev and Sukatsheva [3]. Venational abbreviations are as follows: C, costa; Sc, subcosta; R₁, first branch of the radius; Rs, radial sector; M, media; CuA, anterior cubitus, CuP, posterior cubitus; A, anal vein; m-cua, the crossvein between media and anterior cubitus.

Figure 1. (A) Paleomap of the late Capitania, showing the South China Block, base map from Scotese [44]; (B) Geographical map of China; (C) Geographical map showing the fossil locality.

Figure 1. (A) Paleomap of the late Capitania, showing the South China Block, base map from Scotese [44]; (B) Geographical map of China; (C) Geographical map showing the fossil locality.

3. Systematic Paleontology

Order Mecoptera Packard, 1886

Family Sinoagetopanorpidae fam. nov.

(ZooBank LSID urn:lsid:zoobank.org:act:D66F0AE9-EB35-4672-86D5-6576ED6D1330)

Type genus. Sinoagetopanorpa Lin, Nel and Huang, 2010.

Diagnosis. Male genitalia clip-shaped, medium-sized; wings broad, oval-shaped, covered with dark color, a hyaline rounded triangular spot at apex of interface between each Rs and M branches (occasionally absent). In forewing, costal area broad, Sc armed with three to four elongated branches that evenly developed; R₁ more or less curved apically; Rs five-branched, Rs₄ bifurcated into two branches; M six-branched (occasionally five-branched), M₂ two-branched, M₄ two-branched (occasionally single); A₃ short, occasionally present. In hind wing, costal area broad, Sc single; R₁ forking into two or three branches; Rs five-branched, Rs₄ forking into two branches; M five-branched, M₂ two-branched, M₄ single.

Genera included. Sinoagetopanorpa Lin, Nel and Huang, 2010, Raragetopanorpa gen. nov. and Permoagetopanorpa gen. nov.

Sinoagetopanorpa Lin, Nel and Huang, 2010.

(ZooBank LSID urn:lsid:zoobank.org:act:26971A6F-9533-43B2-B78B-D4D49955346B).

Type species. Sinoagetopanorpa permiana Lin, Nel and Huang, 2010.

Other species. S. nigra sp. nov., S. rotunda sp. nov., S. lini sp. nov., S. minuta sp. nov., S. elegans sp. nov., S. grimaldii sp. nov. and S. magna sp. nov.

Revised diagnosis. Forewing, Sc with three evenly developed elongated branches; M with six branches, A₃ present in some cases. Hind wing, R₁ with two branches or three branches.

Sinoagetopanorpa permiana Lin, Nel and Huang, 2010.

(Figure 2, Figure 3 and Figure 19A; ZooBank LSID urn:lsid:zoobank.org:act:B88A8779-1E3F-4D7F-9D25-B42FCEA742C3).

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Material. Twenty-four specimens, eleven specimens with part and counterpart, and ten complete or nearly so. Holotype, NIGP143428, wing base lacking a small part, with part and counterpart (Figure 2 and Figure 3A,B); from the Yinping Formation, Chaohu City, China (Lin et al. [31], Figure 1, Figure 2, Figure 3 and Figure 4).

Paratypes, NIGP200888 (Figure 3C,D), a complete forewing, with part and counterpart; NIGP200889 (Figure 3E,F), a forewing lacking a small part of apex, with part and counterpart; NIGP200890 (Figure 3G,H), a complete forewing, with part and counterpart. Other unillustrated specimens: NIGP200891, NIGP200892, NIGP200893, NIGP200894, NIGP200895, NIGP200896, NIGP200897, NIGP200898, NIGP200899, NIGP200900, NIGP200901, NIGP200902, NIGP200903, NIGP200904, NIGP200905, NIGP200906, NIGP200907, NIGP200908, NIGP200909, NIGP200910 and NIGP200911.

Revised diagnosis. Forewing moderate in size, covered with dense dark-colored spots, a hyaline rounded triangular spot at apex of each interface between Rs and M branches.

Revised description. Forewing length 5.6–7.9 mm, width 2.9–4.0 mm, L/W 1.9–2.2; apex somewhat rounded; dark color lessening from wing apex toward wing base, a large patch of dark color at apical wing, basal wing with numerous dark-colored spots, costal area with 5–6 hyaline patches that devoid of dark color, a hyaline rounded triangular spot that devoid of dark color at apex of each interface between Rs and M branches; Sc terminated at about 4/5 of wing, with three evenly developed elongated branches; R₁ single, curved slightly apically; pterostigma large, with almost a half below the apical R₁; Rs five-branched, Rs₄ bifurcated into two branches, Rs₁ slightly curved upwards, Rs₁₊₂ fork does not reach the level of M_2a+b fork; a crossvein connected near Rs₁₊₂ fork and Rs₃, stem Rs₃₊₄ and stem M₁₊₂, Rs_4b and M₁, respectively; M six-branched, M₂ bifurcated into two branches; the forking patterns of the three branches of M₃₊₄ variable; most specimens with M₃ single and M₄ two-branched, some with M₃ two-branched and M₄ single, and the other with the three branches of M₃₊₄ forking at one point; stem M₁₊₂ equal to or longer than stem M₃₊₄, a crossvein connecting stems M₂ and M₃, crossvein m-cua connecting stem M₄ (or posterior branch of M₄) and CuA; CuA curved apically, CuP single, straight; the crossvein between basal CuA and CuP oblique to horizontal; the holotypic specimen with R₁ + Rs fork proximal to the first fork of Sc and M + CuA fork, M + CuA fork slightly proximal to the first fork of Sc; most paratypic specimens with M + CuA fork proximal to R₁ + Rs fork and R₁ + Rs fork proximal to the first fork of Sc; two anal veins visible, a crossvein connecting each other near base.

Remarks. The holotype is slightly deformed, so the original line drawings (see Lin et al. [31]: Figure 3 and Figure 4) are inaccurate. The upper branch of CuA in the original line drawing is in fact the lower branch of M₄ (M_4b).

Sinoagetopanorpa nigra sp. nov.

(Figure 4 and Figure 19B; ZooBank LSID urn:lsid:zoobank.org:act:CAF12387-A3EA-4355-AF15-AAAA840CE460).

Etymology. The specific name is derived from the Latin word nigra, dark, referring to the dark-colored wing.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Forewing almost fully with dark colors, absence of dark-colored spots, absence of a hyaline rounded triangular spot at apex of each interface between Rs and M branches; R₁₊₂ fork near the level of M_2a+b fork.

Material. Holotype, NIGP200912, a complete forewing, with part and counterpart (Figure 4 and Figure 19B).

Description. Forewing length 5.6 mm, width 3.0 mm, W/L 1.9; apex rounded and base slightly shrunken; wing almost fully covered with dark color, with three small hyaline patches at costal area and seven small hyaline spots at wing base; Sc terminated at 2/3 of wing, apical Sc₃ extending with the same direction as basal stem Sc; R₁ moderately curved apically; Rs five-branched, stem Rs₁₊₂ length 1.2 mm, stem Rs₃₊₄ length 0.3 mm, stem Rs_4a+b shorter than its branches; a crossvein connecting Rs₁₊₂ fork and Rs₃; Rs merged with R₁ at a distance of 1.5 mm from wing base; a crossvein connecting stem Rs₃₊₄ and stem M₁₊₂, Rs_4b and M₁, respectively; M with six branches, stem M₁₊₂ as long as stem M₃₊₄; both M₂ and M₄ bifurcated into two branches; stem M₄ length 0.2 mm, a crossvein connecting stem M₂ and M₃, crossvein m-cua connecting basal M_4b and CuA; CuA curved after the connection with corossvein m-cua, the crossvein between basal CuA and CuP oblique; CuP straight, apically curved; M + CuA fork proximal to R₁ + Rs fork, R₁ + Rs fork proximal to the first fork of Sc; two anal veins visible, a crossvein connecting A₁ and A₂ near base.

Sinoagetopanorpa rotunda sp. nov.

(Figure 5 and Figure 19C; ZooBank LSID urn:lsid:zoobank.org:act:9E2C0D32-5E2C-44E1-B69D-FDD9907493C6).

Etymology. The specific name is derived from the Latin rotunda, rounded, indicating the rounded wing shape.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Forewing distinctly oval-shaped, absence of dark-colored spots; a hyaline rounded triangular spot at apex of interface between each Rs and M branches; R₁ distinctly curved apically.

Material. Three specimens. Holotype, NIGP200913, a complete forewing, with part and counterpart (Figure 5A,B and Figure 19C). Paratypes, NIGP200914, a complete forewing, with part and counterpart (Figure 5C,D,G); NIGP200915, a forewing lacking base, with part and counterpart (Figure 5E,F,H).

Description. Forewing broad, broadest area at the 4/5 of wing, length 7.1 mm, width 4.1 mm, L/W 1.7; some elongated hyaline patches developed at anterior and basal wing, and a hyaline rounded triangular spot at apex of each interface between Rs and M branches; crossveins usually accompanied with a small hyaline patch; pterostigma large, with almost a half below the apical R₁; Sc terminated at 2/3 of wing, with three evenly developed elongated branches; R₁ single, curved distinctly in the pterostigma; Rs five-branched, Rs₁₊₂ fork proximal to M_2a+b fork; stem Rs₁₊₂ 4 times as long as stem Rs₃₊₄; Rs₁ curved upwards in middle; stem Rs_4a+b as long as its branches; a crossvein connecting basal Rs₂ and Rs₃; M six-branched, M₂ and M₄ forking into two branches; stem M₁₊₂ slightly longer than M₃₊₄ and as long as stem M_2a+b; basal Rs_4a and M₁, stem Rs₃₊₄ and stem M₁₊₂, stem M_2a+b and M₃ connected by a crossvein, respectively, crossvein m-cua connecting basal M_4b and CuA; CuA and CuP simple, CuA curved after the crossvein m-cua; the crossvein between CuA and CuP curved; R₁ + Rs fork and M + CuA fork nearly at the same level and proximal to the first fork of Sc; A₁ and A₂ single, a crossvein connecting each other near base.

Paratypes. NIGP200914, a complete forewing, with part and counterpart (Figure 5C,D,G), length 6.9 mm, width 4.0 mm, L/W ratio 1.7; lower margin in the middle concaved obviously; stem Rs₁₊₂ twice as long as stem Rs₃₊₄; stem M₁₊₂ slightly longer than M₃₊₄ and nearly twice as long as stem M_2a+b; M₃ two-branched, M₄ single, stem M_3a+b short; crossvein m-cua connecting CuA with basal M₄.

NIGP200915 (Figure 5E,F,H), a forewing with wing base not preserved, with part and counterpart, length 6.7 mm (as preserved), width 3.9 mm; stem Rs₁₊₂ 3 times as long as stem Rs₃₊₄; stem M₁₊₂ as long as stem M₃₊₄ and nearly twice as long as stem M_2a+b; M₃ two-branched, M₄ single, stem M_3a+b distinctly short; crossvein m-cua connecting CuA and basal M₄.

Sinoagetopanorpa lini sp. nov.

(Figure 6, Figure 7, Figure 8 and Figure 19D; ZooBank LSID urn:lsid:zoobank.org:act:CFDDAB8C-8A18-4A32-AC84-331AE5E360B9).

Etymology. The specific name is in honor of the late paleoentomologist, Prof. Qibin Lin, for his extraordinary contribution to the paleoentomology of the Yinping Formation.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Wing without dark-colored spots; a hyaline rounded triangular spot at apex of interface between each Rs and M branches; forewing with Rs₁₊₂ fork proximal to M_2a+b fork; hind wing devoid of dark color at wing base; R₁ bifurcating into two terminal branches.

Material. Four specimens, two with part and counterpart. Holotype, sex unknown, NIGP200916, with part and counterpart (Figure 6 and Figure 7), a specimen preserved with part of body and four wings, abdomen segments detected; left forewing and right hind wing overlap with each other, left forewing upturned. Paratypes, NIGP200917, a complete forewing, with part and counterpart (Figure 8 and Figure 19D); other unillustrated specimens: NIGP200918 and NIGP200919.

Description. Body length 5.3 mm (as preserved), head and thorax preserved obscurely, thorax medium size; abdomen with seven clearly discernible segments, length shorter than width, last two segments narrowed; genitalia relatively small compared with abdomen, clip-shaped, basistyles and dististyles lacking details; the left middle leg preserved with femur, tibia and tarsus; femur robust, length 1.5 mm (as preserved); tibia length 1.9 mm; five tarsi segments preserved (with total length 1.5 mm); tarsomeres gradually shorten from base towards apex; two front legs and left hind leg partly preserved.

Forewing relatively elongated, broadest at 2/3 of wing, right forewing length 7.5 mm, width 3.5 mm, L/W 2.1 (Figure 6E,F and Figure 7C); three small hyaline patches located at costal area; R₁ single and curved apically; Rs five-branched, a terminal fork visible at right forewing of holotype (Figure 7C), left forewing (Figure 7B) lacking the terminal fork; stem Rs₁₊₂ about twice as long as stem Rs₃₊₄, Rs₁₊₂ fork proximal to M₁₊₂ fork, a crossvein connecting basal Rs₂ and Rs₃, basal Rs_4b and M₁, stem Rs₃₊₄ and stem M₁₊₂, respectively; M six-branched, stem M₁₊₂ 1.5 times as along as stem M₃₊₄, both M₂ and M₄ two-branched; a crossvein connecting stem M_2a+b and M₃, crossvein m-cua connecting CuA with M near M_4a+b fork; CuA curved after the crossvein m-cua, CuP single, straight; the crossvein connecting basal CuA and CuP nearly horizontal; R₁ + Rs fork at the same level as M + CuA fork and proximal to the first fork of Sc; two anal veins visible, a crossvein connecting A₁ and A₂.

Hind wing smaller than forewing; left hind wing length 6.4 mm, width 3.2 mm, L/W 2.0 (Figure 6G,H and Figure 7D,E); wing with dense dark color, a large hyaline patch stretched from the middle part of wing base to middle wing, a hyaline rounded triangular spot at apex of interface between each Rs and M branches; costal area broad, Sc single, terminated at middle wing, curved apically; R₁ bifurcated into two branches at middle wing; Rs five-branched, stem Rs₁₊₂ more than 3 times as long as stem Rs₃₊₄; stem Rs_4a+b longer than its branches, Rs₁₊₂ forking at the same level as M₁₊₂ fork; a crossvein between R_1b and Rs₁, basal Rs₂ and Rs₃, Rs₃ and Rs_4a, respectively, and the crossveins inside the small spots devoid of dark color; M five-branched, M₂ two-branched, stem M₁₊₂ as long as stem M₃₊₄ and M_2a+b; basal stem Rs_4a+b and stem M₁₊₂, Rs_4b and M₁, stem M_2a+b and M₃ connected by a crossvein, respectively; crossvein m-cua connecting M₃₊₄ fork and CuA; CuA and CuP straight, the crossvein between basal CuA and CuP oblique; left forewing with R₁ + Rs fork slightly proximal to M + CuA fork; right forewing with R₁ + Rs fork distinctly proximal to M + CuA fork; two straight anal veins visible.

Paratypes: NIGP200917 (Figure 8 and Figure 19D), forewing, length 6.4 mm, width 3.0 mm, W/L 2.1; three relatively large irregular hyaline patches covered at the area of costa, subcosta and along the R₁, a hyaline rounded triangular spot at apex of each interface between Rs_2–4 and M branches, some crossveins in spots and approximately 10 small spots at wing base; stem M₁₊₂ slightly longer than stem M₃₊₄ and twice as long as stem M_2a+b; the three branches of M₃₊₄ nearly forking at one point.

Remarks. The dark color inside the forewings of the holotype is too poorly preserved to reconstruct.

Sinoagetopanorpa minuta sp. nov.

(Figure 9 and Figure 19E; ZooBank LSID urn:lsid:zoobank.org:act:512A5737-065F-49D8-BDFB-68F002A18129).

Etymology. The specific name is derived from the Latin minuta, small, indicating the small wing size.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Forewing small, a hyaline rounded triangular spot at end of each interface of Rs and M branches; Rs₄ forking late, A₃ short, the area between A₃ and wing margin narrow.

Material. Only holotype (NIGP200920) examined, a nearly complete forewing, with part and counterpart (Figure 9 and Figure 19E).

Description. Forewing with apex rounded and broad, length 4.8 mm, width 2.6 mm, L/W 1.9; wing with dark color, more than 10 irregular hyaline patches focused on anterior and basal wing, some crossveins accompanied with small hyaline patches, a hyaline rounded triangular spot at apex of each interface of Rs and M_1–3 branches; Sc terminated at a distance of 2/3 from wing base; R₁ single and nearly straight; Rs five-branched, stem Rs₁₊₂ length 0.6 mm, stem Rs₃₊₄ length 0.3 mm; Rs₁₊₂ forking at the same level as M₁₊₂ fork; Rs₄ forking apically; stem Rs_4a+b twice as long as its branches; a crossvein connecting basal Rs₂ and Rs₃; M six-branched, M₂ and M₄ both bifurcated into two branches, stem M₁₊₂ as long as stem M_2a+b and slightly longer than stem M₃₊₄, stem M_4a+b very short; Rs₃₊₄ fork and stem M₁₊₂, Rs_4a+b fork and M₁, stem M_2a+b and M₃ connected by a crossvein, respectively, crossvein m-cua connecting M_4a+b fork and CuA; CuA curved after the crossvein m-cua, CuP straight; the crossvein between CuA and CuP robust and nearly horizontal; M + CuA fork proximal to R₁ + Rs fork, R₁ + Rs fork slightly proximal to the first fork of Sc; three anal veins visible, A₃ short, very close to wing margin.

Sinoagetopanorpa elegans sp. nov.

(Figure 10, Figure 11 and Figure 19F; ZooBank LSID urn:lsid:zoobank.org:act:7BE01613-3A97-4141-9F94-248339997070).

Etymology. The specific epithet is derived from the Latin elegans, indicating the well-preserved four wings.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Forewing with numerous dark-colored spots, base narrow, a hyaline rounded triangular spot at apex of each interface of Rs and M branches; Rs_4a+b forked late, A₃ distinctly developed, the area between A₃ and wing margin broad. Hind wing with Rs_4a+b forked very late, R₁ with three terminal branches.

Material. Holotype, NIGP200921 (Figure 10 and Figure 11), two forewings and two hind wings preserved in one specimen, interpreted as one individual. One forewing is well-preserved, the other forewing lacking apex; two hind wings overlap with each other, poorly preserved.

Description. Forewing with apex rounded, base obviously shrunken, the complete forewing length 5.6 mm, width 2.6 mm, L/M 2.2; dark color denser at the apical wing than basal wing, costal area with 5–6 hyaline patches; Sc terminated at a distance of 3.9 mm from wing base; R₁ single, smoothly curved near apex; pterostigma large, half below the apical R₁; Rs five-branched, Rs₄ bifurcated into two terminal branches, Rs₁ curved upwards, Rs₁₊₂ fork at the same level as M₁₊₂ fork, stem Rs₁₊₂ 1.5 times as long as stem Rs₃₊₄, stem Rs_4a+b long and 1.5 times as long as its branches; M six-branched, M₂ bifurcating into two branches, stem M₁₊₂ about 1.5–1.7 times as long as stem M₃₊₄, the three branches of M₃₊₄ forking close, resulting in one forewing with M₃ two-branched and M₄ single, the other forewing with M₃ single and M₄ two-branched; a crossvein connecting stem Rs₃₊₄ and M₁₊₂, stem M_2a+b and M₃, respectively, crossvein m-cua connecting basal M₄ (or M_4b) and CuA; CuA curved apically, CuP straight and single; M + CuA proximal to R₁ + Rs, R₁ + Rs proximal to the first fork of Sc; three anal veins, A₃ short, the area between A₃ and wing margin broad.

Hind wing poorly preserved with dark color; costal area broad, ca. 3 times as wide as subcostal area; Sc abruptly curved to costa apically; R₁ forking near the same level as apical Sc; Rs five-branched, Rs₄ bifurcated into two branches, one hind wing with stem Rs₁₊₂ slightly longer than Rs₃₊₄, the other hind wing with Rs₁₊₂ nearly twice as long as stem Rs₃₊₄; Rs_4a+b fork distinctly distad to M_2a+b fork; a crossvein connecting stem Rs₃₊₄ and stem M₁₊₂; M five-branched, M₂ with two branches, stem M₁₊₂ longer than stem M₃₊₄; CuA and CuP single and straight, anal veins absent.

Sinoagetopanorpa grimaldii sp. nov.

(Figure 12 and Figure 19G; ZooBank LSID urn:lsid:zoobank.org:act:40BB5B06-8910-4165-8253-B7D1591D0E16).

Etymology. The specific name is dedicated to the famous American paleoentomologist David Grimaldi.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Forewing with two distinct dark stripes across the wing, with some dark-colored spots, apex of each Rs and M branches covered with a dark-colored spots and absence of the hyaline triangular spot.

Material. Four specimens, two of them with part and counterpart. Holotype, NIGP200922, a complete forewing (Figure 12A,B and Figure 19G). Paratypes, NIGP200923, a forewing lacking apex (Figure 12C,D); NIGP200924, a forewing lacking wing base with part and counterpart; NIGP200925, lacking a small part of wing apex, with part and counterpart.

Description. Holotype, NIGP200922, forewing length 8.0 mm, width 4.0 mm, W/L 2.0, widest at middle wing, obviously tapering to base and apex; two dark stripes vertically lined across the wing, the larger one located at apex of R₁, the smaller one located at Sc₃; many dark-colored spots scattering at wing apex, middle and basal wing, but not combined into stripe; Sc terminated at 3/4 of wing; R₁ curved apically; Rs five-branched, stem Rs₁₊₂ twice as long as stem Rs₃₊₄, Rs₁₊₂ forking at the same level as M₁₊₂ fork, stem Rs_4a+b shorter than its branches; M six-branched, stem M₁₊₂ slightly longer than M₃₊₄ and M_2a+b; M₃ two-branched, M₄ single, stem M₃ short; a crossvein connecting Rs_4b and M₁, stem M₁₊₂ and basal Rs_4a+b, stem M_2a+b and M_3a, respectively; crossvein m-cua connecting basal M₄ and CuA; CuA single, curved apically, merged with M at the level of first Sc fork; CuP single, apically curved, the crossvein between basal CuA and CuP oblique; R₁ + Rs fork distinctly proximal to M + CuA and the first fork of Sc; two long anal veins, A₁ leaned to CuP apically, A₂ terminated at 1/3 of wing, a crossvein connecting A₁ and A₂.

Paratypes: NIGP200923 (Figure 12C,D), forewing length 6.9 mm (as preserved), width 3.5 mm; stem M₁₊₂ as long as stem M₃₊₄, the three branches of M₃₊₄ forking at one point. NIGP200924, forewing length 6.9 mm (as preserved), width 3.6 mm; stem Rs₁₊₂ 3 times as long as stem Rs₃₊₄; M₃ single, M₄ two-branched, stem M₁₊₂ distinctly longer than stem M₃₊₄. NIGP200925; forewing length 8.3 mm (as preserved), width 3.9 mm, deformed and overlapped by another wing fragment; M₃ single, M₄ two-branched, stem M₁₊₂ slightly longer than stem M₃₊₄.

Sinoagetopanorpa magna sp. nov.

(Figure 13 and Figure 19H; ZooBank LSID urn:lsid:zoobank.org:act:D309ED60-3469-4987-AEBA-56BCFF4B615A).

Etymology. The specific name is derived from the Latin word magna, large, indicating the large-sized wing.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Forewing relatively large, with two dark stripes, numerous small dark-colored spots at sides of the stripes; a distinct crossvein connecting base of Rs₁ and R₁.

Material. Holotype NIGP200926, with part and counterpart (Figure 13 and Figure 19H), with veins well-preserved but lacking wing apex and part of base.

Description. Forewing length 8.2 mm (as preserved), estimated length 10.0 mm, width 5.0 mm, with two distinct colored stripes vertically lined across the wing, one located at apex of R₁ and tapering to posterior wing, the other one located at Sc₃; numerous small dark-colored spots scattering at sides of the stripes, each spot apart from the others; Sc terminated at a distance of 7.5 mm from wing base; R₁ curved apically; Rs five-branched, stem Rs₁₊₂ length 1.3 mm, stem Rs₃₊₄ length 0.8 mm, stem Rs_4a+b length 2.2 mm, Rs₁₊₂ fork slightly proximal to M₁₊₂ fork, a crossvein connecting basal Rs₁ and R₁; M six-branched, stem M₁₊₂ length 1.4 mm, stem M_2a+b length 1.1 mm, stem M₃₊₄ length 1.0 mm, M₃₊₄ three-branched and forking at one point; stem M₁₊₂ and Rs₃₊₄ fork, stem M_2a+b and upper branch of M₃₊₄ connected by a crossvein, respectively; crossvein m-cua connecting lower branch of M₃₊₄ and CuA; CuA curved after the crossvein m-cua, CuP single and curved apically; the crossvein between basal CuA and CuP robust and nearly horizontal; two anal veins detected, A₁ leaned to CuP near apex; A₂ terminated at a distance of 4.3 mm from wing base.

Raragetopanorpa gen. nov.

(ZooBank LSID urn:lsid:zoobank.org:act:61003EF7-F803-4261-9AE0-6CF9B65FD5B9).

Etymology. The generic name combines the Latin word rara, rare, indicating only one specimen has been found, and a mecopteran generic name Agetopanorpa.

Diagnosis. Sc with three evenly developed elongated branches; M five-branched with M₂ two-branched and M₄ single.

Type species.Raragetopanorpa zhangi gen. et sp. nov., genus monotypic.

Raragetopanorpa zhangi sp. nov.

(Figure 14 and Figure 19I; ZooBank LSID urn:lsid:zoobank.org:act:54B79578-0A41-4D0C-9983-6D52E4723AFD).

Etymology. The species name zhangi is in honor of the late paleoentomologist, Prof. Junfeng Zhang, for his contribution to Chinese paleoentomology.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. As for the genus.

Material. Holotype, NIGP200927, a nearly complete forewing with base poorly preserved (Figure 14 and Figure 19I).

Description. Forewing with apex somewhat rounded, length 6.4 mm, width 3.3 mm, L/W 1.9; wing with dark color, several distinct dark-colored spots at top of middle wing, costal area with four hyaline spots, a hyaline rounded triangular spot at apex of each Rs and M branches, some crossveins inside a small spot; Sc terminated distad to the level of Rs_4a+b fork; R₁ single, straight, smoothly curved apically; Rs five-branched, Rs₁ curved, stem Rs₁₊₂ length 1.0 mm, stem Rs₃₊₄ length 0.3 mm, stem Rs_4a+b as long as its branches; M five-branched, stem M₁₊₂ slightly longer than stem M₃₊₄; stem M_2a+b as long as stem M₃₊₄; basal Rs_4a+b and M₁₊₂, basal stem Rs₄ and M₁, middle of M_2a+b and M₃ connected by a crossvein, respectively, crossvein m-cua connecting basal M₄ and CuA; CuA curved after crossvein m-cua, merged with M at the same level as R₁ + Rs fork and proximal to the first fork of Sc; CuP single and straight; the crossvein between basal CuA and CuP oblique; two anal veins detected, A₁ curved at basal half, A₂ shorter and curved downwards at apex.

Permoagetopanorpa gen. nov.

(ZooBank LSID urn:lsid:zoobank.org:act:C1F1E1AB-A4B2-42DA-A8EF-E225C91641BE).

Etymology. The generic name combines Permo, the Permian period, and mecopteran generic name Agetopanorpa.

Diagnosis. Forewing, Sc with four evenly developed elongated branches; M six-branched, with M₂ and M₄ bifurcated into two branches.

Type species. Permoagetopanorpa yinpingensis gen. et sp. nov.

Other species. Permoagetopanorpa incompleta sp. nov.

Permoagetopanorpa yinpingensis sp. nov.

(Figure 15 and Figure 19J; ZooBank LSID urn:lsid:zoobank.org:act:344ED4C6-A618-4729-B6BC-C77F22D9976A).

Etymology. The species name is derived from the Yinping Formation, where the specimen was collected.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Forewing moderately large in this group, Sc branches long, Sc₃, Sc₄, and stem Sc forming relatively small angles.

Material. Holotype, NIGP200928, a specimen lacking some part of apex, with part and counterpart (Figure 15 and Figure 19J).

Description. Forewing relatively broad, length 8.0 mm, width 4.3 mm, broadest at 2/3 of wing; wing with dense dark color, five hyaline patches at costal area, a hyaline rounded triangular spot at each apex between Rs₁, Rs₂ and Rs₃; Sc terminated at a distance of 5.9 mm from wing base, the first fork of Sc at a distance of 2.3 mm from wing base; R₁ single and curved apically; Rs five-branched, stem Rs₁₊₂ length 1.2 mm, stem Rs₃₊₄ length 0.3 mm, stem Rs_4a+b length 1.8 mm, Rs₁₊₂ fork distad to M₁₊₂ fork, Rs₁ curved upwards, basal Rs₂ and Rs₃ connected by a crossvein; M six-branched, M₂ and M₄ bifurcated into two branches, stem M₁₊₂ length 1.3 mm, stem M₃₊₄ length 0.9 mm; stem Rs₃₊₄ and stem M₁₊₂, stem M_2a+b and M₃ connected by a crossvein, respectively; the crossvein m-cua indistinct, inferred from the sharply curved M_4a+b; CuA curved at apical part; CuA merged with M at the same level as R₁ + Rs fork and proximal to the first fork of Sc; CuP straight; two anal veins detected; a crossvein connecting A₁ and A₂.

Permoagetopanorpa incompleta sp. nov.

(Figure 16 and Figure 19K; ZooBank LSID urn:lsid:zoobank.org:act:420F6ACA-BA85-49ED-8A51-57B2C5299F4C).

Etymology. The specific name is derived from the incompletely preserved forewing.

Type locality and horizon. Yinping Mountain, Chaohu City, Anhui Province, China; Yinping Formation (Capitanian).

Diagnosis. Forewing relatively small, Sc branches relatively short, Sc₃, Sc₄ and Sc stem forming relatively large angles.

Material. Holotype, NIGP200929, lacking a large part of wing base, overlapped by other wing fragment at anal area, with part and counterpart (Figure 16 and Figure 19K).

Description. Forewing covered with dense dark color, wing length 5.2 mm (as preserved), width 3.1 mm, with some small hyaline patches at costal area; a hyaline rounded triangular spot at apex of each interface between Rs and M_1–3 branches; Sc₃, Sc₄ and Sc stem forming nearly 60-degree angles, Sc₁ and Sc₂ forming a 30-degree angle, each branch of Sc nearly the same length; R₁ single and curved apically; Rs five-branched, stem Rs₁₊₂ length 0.7 mm, stem Rs₃₊₄ length 0.5 mm, Rs_4a+b longer than its branches, Rs₁₊₂ forking at the same level as M₁₊₂ fork; a possible crossvein inside a spot connecting basal Rs₂ and Rs₃; M six-branched, with M₂ and M₄ forking into two branches, stem M₁₊₂ length 0.9 mm, stem M₃₊₄ length 0.7 mm, stem M_2a+b length 0.8 mm, stem M_4a+b short; a crossvein connecting stem Rs₃₊₄ and stem M₁₊₂, stem M_2a+b and M₃; CuA curved at the apical part; other veins not preserved.

Hind wings of Sinoagetopanorpidae fam. nov.

The hind wings of Sinoageotpanorpidae fam. nov. are often preserved as isolated wings. Fourteen isolated hind wings (NIGP200930, NIGP200931, NIGP200932, NIGP200933, NIGP200934, NIGP200935, NIGP200936, NIGP200937, NIGP200938, NIGP200939, NIGP200940, NIGP200941, NIGP200942 and NIGP200943) were found (four with part and counterpart; NIGP200932 preserved a pair of hind wings). Two hind wings accompanied with forewings (S. lini. sp. nov. and S. elegans sp. nov.), and the rest of hind wings remain elusive in terms of their systematic positions. Similar to forewings, the hind wings are very stable in venation, with two types of venational patterns distinguished. The most common one (13/14) with three-branched R₁ is represented by S. elegans sp. nov., but the hind wings of S. elegans sp. nov. are too incomplete with poor preservation to compare with other isolated hind wings; thus, no isolated hind wings are reluctantly attributed to S. elegans sp. nov. The rare one (one specimen) with two-branched R₁ is represented by S. lini sp. nov.

The specimen NIGP200930 (Figure 17A,B and Figure 18A) is a well-preserved hind wing and described as follows: wing broad, base narrow, broadest at near middle wing, length 6.6 mm, width 3.6 mm, L/W 1.8; wing apex with dark color, costal area with three hyaline patches, basal one oval shaped and large; basal wing devoid of dark color; lines of dark color along longitudinal veins; costal area broad, ca. 3 times as wide as subcostal area; Sc abruptly curved to costa near apex; R₁ with three evenly developed terminal branches, R_1b paralleled to R_1c, forking near the level of apical Sc; Rs five-branched, with Rs₄ bifurcated into two branches, stem Rs₁₊₂ more than twice as long as stem Rs₃₊₄, a crossvein connected near Rs₁₊₂ fork and Rs₃, stem Rs₃₊₄ and M₁₊₂, Rs_4b and M₁, respectively; M five-branched, M₂ two-branched, M₄ single, stem M₁₊₂ as long as stem M₃₊₄; a crossvein connecting stem M_2a+b and M₃, crossvein m-cua connecting basal M₄ and CuA; CuA straight, connected with M near wing base; CuP straight, the crossvein between basal CuA and CuP nearly horizontal; A₁ straight, connected with CuP near wing base; A₂ with one long branch and one short branch, forking near wing base; a crossvein connecting basal A₂ and A₁, A₃ very short and close to wing margin.

Key to genera and species of Sinoagetopanorpidae fam. nov.

• Sc with four evenly developed elongated branches……………2 Permoagetopanorpa gen. nov.

  -

  Sc with three evenly developed elongated branches………………………………3

• Wing relatively large; Sc branches relatively long; Sc₃, Sc₄ and stem Sc forming relatively small angles………………………………Permoagetopanorpa yinpingensis sp. nov.

  -

  Wing relatively small; Sc branches relatively short; Sc₃, Sc₄ and stem Sc forming relatively large angles………………………Permoagetopanorpa incompleta sp. nov.

• M six-branched…………………………………………………………4 Sinoagetopanorpa

  -

  M five-branched…………………………… Raragetopanorpa zhangi gen. et sp. nov.

• Wing covered with numeral dark-colored spots and some spots fused in stripes; a round dark-colored spot at apex of each Rs and M branches……………………………5

  -

  A hyaline rounded triangular spot at apex of each interface between Rs and M branches………………………………………………………………………………6

  -

  Absence of the hyaline rounded triangular spot at apex of each interface between Rs and M branches; R₁₊₂ fork near the level of M_2a+b fork……… Sinoagetopanorpa nigra sp. nov.

• Wing moderately large; fewer dark-colored spots at sides of stripes…………Sinoagetopanorpa grimaldii sp. nov.

  -

  Wing relatively large, more dark-colored spots at sides of stripes; a crossvein connecting base of Rs₁ and R₁…………………… Sinoagetopanorpa magna sp. nov.

• A₃ developed, Rs_4a+b forking late……………………………………………………………7

  -

  A₃ absent, Rs_4a+b forking early…………………………………………………………8

• Wing with dense dark color; the area between A₃ and wing margin narrow………………………………………………………Sinoagetopanorpa minuta sp. nov.

  -

  Wing with numerous dark-colored spots; the area between A₃ and wing margin broad; R₁ with three terminal branches in hind wing ………………………………………………Sinoagetopanorpa elegans sp. nov.

• Wing with dense colored spots…………Sinoagetopanorpa permiana Lin, Nel and Huang, 2010
• Wing with dense dark color; hind wing with R₁ two-branched………………………Sinoagetopanorpa lini sp. nov.
• Wing broad, with dense dark color; apex of R₁ distinctly curved………………………………………………… Sinoagetopanorpa rotunda sp. nov.

Figure 19. Line drawings of all sinoagetopanorpid species: (A) Sinoagetopanorpa permiana Lin, Nel and Huang, 2010, NIGP200888 (paratype); (B) S. nigra sp. nov., NIGP200912 (holotype); (C) S. rotunda sp. nov., NIGP200913 (holotype); (D) S. lini sp. nov., NIGP200917 (paratype); (E) S. minuta sp. nov., NIGP200920 (holotype); (F) S. elegans sp. nov., NIGP200921 (holotype); (G) S. grimaldii sp. nov., NIGP200922 (holotype) (mirror image); (H) S. magna sp. nov., NIGP20926 (holotype); (I) Raragetopanorpa zhangi sp. nov., NIGP200927 (holotype); (J) Permoagetopanorpa yinpingensis sp. nov., NIGP200928 (holotype); (K) P. incompleta sp. nov., NIGP200929 (holotype). Scale bar represents 1 mm.

Figure 19. Line drawings of all sinoagetopanorpid species: (A) Sinoagetopanorpa permiana Lin, Nel and Huang, 2010, NIGP200888 (paratype); (B) S. nigra sp. nov., NIGP200912 (holotype); (C) S. rotunda sp. nov., NIGP200913 (holotype); (D) S. lini sp. nov., NIGP200917 (paratype); (E) S. minuta sp. nov., NIGP200920 (holotype); (F) S. elegans sp. nov., NIGP200921 (holotype); (G) S. grimaldii sp. nov., NIGP200922 (holotype) (mirror image); (H) S. magna sp. nov., NIGP20926 (holotype); (I) Raragetopanorpa zhangi sp. nov., NIGP200927 (holotype); (J) Permoagetopanorpa yinpingensis sp. nov., NIGP200928 (holotype); (K) P. incompleta sp. nov., NIGP200929 (holotype). Scale bar represents 1 mm.

4. Discussion

Sinoagetopanorpidae fam. nov. resemble members of the subfamily Agetopanorpinae of Permochoristidae in venation. Both groups are characterized by the following venational characteristics: Sc usually with three evenly developed elongated branches, Rs with five branches and M generally with six branches. However, it is very conspicuous that sinoagetopanorpids possess broad oval-shaped forewings with broad costal area, and the forking patterns of the three branches of the M₃₊₄ forks are varied: M₄ bifurcating into two branches and M₃ single or M₃ bifurcating into two branches and M₄ single, or even three branches of M₃₊₄ forking at the same point. With the consideration of these different forewing characteristics, we erected the new family Sinoagetopanorpidae fam. nov.

Sinoagetopanorpidae resemble Choristopsychidae Martynov, 1937 in having broad oval-shaped wings: Sinoagetopanorpidae possess a wing aspect ratio of 1.7–2.2, while 1.5–2.0 in Choristopsychidae, and both families show a broad costal area with three evenly developed branched Sc. Choristopsychidae was placed by many authors in the Permochoristidae family for its venational similarity with Agetopanorpinae [45,46,47]; however, Qiao et al. [48] discovered numerous exquisite specimens from the Middle−Upper Jurassic (originally assigned to the Middle Jurassic) Daohugou biota, and erected the family Choristopsychidae. Sinoagetopanorpidae differ from Choristopsychidae in a combination of the following characteristics: in terms of forewings, Sinoagetopanorpidae have at least five-branched Rs instead of four-branched, six-branched M with three-branched M₃₊₄ instead of five-branched M with two-branched M₃₊₄; in addition, the hind wings of Sinoagetopanorpidae have single Sc instead of two-branched Sc; furthermore, Sinoagetopanorpidae are confined to the Permian strata, whereas Choristopsychidae occurred in the Jurassic.

Based on our study of abundant new specimens, we found that the venational pattern of Sinoagetopanorpidae is rather stable: Sc generally with three branches (except the two new species of Permoagetopanorpa); Rs five-branched; M with six branches where M₂ and M₄ (or M₃) bifurcate into two branches (except for Raragetopanorpa zhangi sp. nov., which possesses a five-branched M with two-branched M₂ and a single M₄) and anal veins generally with two branches, but A₃ detected in S. elegans and S. minuta. To distinguish these species, dark-colored pattens play another important role in species-level classification. In the forewings, four kinds of colored patterns are recognized: (1) the absence of a hyaline rounded triangular spot at the apex of each interface between Rs and M branches; (2) the apex of each Rs and M vein has a dark-colored spot and two dark-colored stripes across the wing; (3) a hyaline rounded triangular spot at the apex of each interface between Rs and M branches, the wing with a dense dark color; and (4) a hyaline rounded triangular spot at the apex of each interface between Rs and M branches, the wing with numerous colored spots.

Our discovery of two specimens preserved with both forewings has some implications for venational variations. The holotype of S. lini sp. nov. possesses the right forewing with Rs₁ armed with a terminal fork, while the left forewing with a single Rs₁. The variation of the terminal fork in the anterior branches of Rs in one individual can be found in other mecopteran families, such as Cimbrophlibiidae [49] and Panorpidae [50,51]. The two forewings of holotype of S. elegans sp. nov. show variation in the forking pattern of the three branches of M₃₊₄: one forewing with M₃ two-branched and M₄ single, but the other with M₄ two-branched and M₃ single, indicating that the forking pattern of M₃₊₄ is unstable. Therefore, we do not regard these characters as an interspecific diagnostic characteristic.

During the Capitanian, the fossil locality was near 32° N on the Northeast Yangtze Platform in the eastern Paleotethys, which split from the Gondwana supercontinent during the Silurian [44,52], and it possibly had a lagoonal paleoenvironment under the large-scale regression [35,38]. The extant known scorpionflies, with no exception, are weak flyers with low dispersal capacity. Therefore, the endemic mecopteran group Sinoagetopanorpidae fam. nov., the representative mecopterans in the Yinping Formation, might have evolved independently on the Yangtze Platform. The new family from the late Capitanian might have become extinct during the end-Guadalupian mass extinction, which was possibly associated with large-scale volcanic activities [53,54].