New fossil Procercopidae ( Hemiptera : Cicadomorpha ) from the Middle Jurassic of Daohugou , Inner Mongolia , China

Anthoscytina Hong, 1983 is the largest genus within the Mesozoic Procercopidae, the stem group of the superfamily Cercopoidea. Herein, we describe two new species from the Middle Jurassic of Daohugou, northeast China. Anthoscytina brevineura Chen, Wang & Zhang, sp. n. and Anthoscytina elegans Chen, Wang & Zhang, sp. n. are established on the basis of new well-preserved fossils. Although these two new species are very similar, some stable differences in tegminal venation and colour patterns confirm their species status. Sinotettegarcta longa Hong, 1986 is transferred to Anthoscytina, and to avoid secondary homonymy, a new name Anthoscytina hongi Chen, Wang & Zhang, nom. n. is proposed for that species. In addition, Anthoscytina aphthosa Ren, Yin & Dou, 1998 and An­ thoscytina macula Hu, Yao & Ren, 2014 are transferred from Anthoscytina to Stellularis Chen, Yao & Ren, 2015.


INTRODUCTION
The Cercopoidea Leach, 1815 is one of the most speciose superfamilies of Cicadomorpha, with nearly 3000 described species attributed to five modern families and three extinct families from the Mesozoic (Hamilton, 2001;Dietrich, 2002;Hu et al., 2012;Wang et al., 2012).Most fossil and extant cercopoids are small insects, usually shorter than 13 mm (Hong, 1983;Wang & Zhang, 2009).Adult cercopoids are commonly called froghoppers because they look like tiny frogs and are very adept at jumping (Burrows, 2003).Their nymphs, known as spittlebugs, cover themselves with foaming spittle to provide protection from predation, parasitism and desiccation (Hamilton, 1982;Li et al., 2013).
The family Procercopidae, as the earliest cercopoid group, is recorded from the Early Jurassic to Early Cretaceous in Germany, Russia, Central Asia, Southeast Asia and China.Anthoscytina Hong, 1983, the largest genus within the Procercopidae, was erected on the basis of a complete tegmen from the Middle Jurassic of Beipiao, Liaoning in China (Hong, 1983).It was previously referred to the family Scytinopteridae Handlirsch, 1906 and later transferred to the Procercopidae (Shcherbakov, 1988).The tegminal lengths reported for species of Anthoscytina range from 10 mm to 15 mm.
Very recently the present authors collected some new giant procercopids from Daohugou in Northeast China, of which some are assigned to the genus Anthoscytina.We report herein on two of these species with tegmens of around 20 mm in length.1983 and A. longa Hong, 1983, respectively.Furthermore, Wang et al. (2012) treated Mesocercopis Hong, 1983 andSinotettegarcta Hong, 1986 as synonyms of Anthoscy tina Hong, 1983, but did not mention the validity of both Mesocercopis longa Hong, 1983 and Sinotettegarcta longa Hong, 1986.For M. longa, the most important characters at the specific level are not included in the original description, so it is impossible to determine its species status until the type specimen is re-examined.Sinotettegarcta longa is similar to A. longa in terms of the pattern in the venation and size, but distinctly differs from the latter in that on the tegmen R is multi-branched and M branches close to the apex of the wing.Remarks.Shcherbakov (1988) revised the generic diagnosis and transferred Cycloscytina reducta Becker-Migdisova, 1949 to this genus.He suggested that Para cicadella Hong, 1983 andParacicadella beipiaoensis Hong, 1983 are junior synonyms of Anthoscytina Hong, Anthoscytina hongi Chen, Wang & Zhang, nom.n. for An thoscytina longa (Hong, 1986: 14-15, Fig. 5, Pl.II: 3) comb.n. (described as Sinotettegarcta longa), a junior secondary homonym of Anthoscytina longa Hong, 1983: 61-62, Fig. 47, Pl. 10: 3. Etymology.The specific epithet is named after Youchong Hong who described the species.
Remarks.This species is very similar to the type species of Anthoscytina, but differs from the latter in having a tegmen with cross veins ir and rm almost at the same level.It Etymology.The specific epithet is derived from the Latin "brevis" (meaning short) and "neurus" (meaning vein), which refers to the extremely short cross vein mcua.
Diagnosis.Body large.Tegmen broad; membrane tinged with longitudinal stripes, and apical margin darkly stained; RA simple, connected with M 1+2 by cross vein rm just distal of junction with cross vein ir; stem M branching into M 1+2 and M 3+4 near base at 0.9 wing length; M 1+2 short, transverse; M 3+4 vertical, rectangular at junction with cross vein mcua, and then transverse; cross vein mcua extremely short; CuA 1 parallel to M, geniculate at junction with cross vein mcua, and then running subparallel to Middle femur slenderer than fore femur, approximately 0.6 mm wide; middle tibia slightly longer than fore tibia, approximately 2.7 mm long; middle tarsus about 1.0 mm long, with three tarsomeres; apical tarsomere longer than mid tarsomere and basitarsomere; two claws and an arolium visible (Figs 2A, D).Hind tibia slender, about 3.5 mm long, with a short lateral spine 2/3 along its length and two rows of tiny teeth apically; hind tibia about 1.8 mm long; basitarsomere and mid tarsomere similar in shape, and taBle 1. Morphometric data of tegmina of the specimens included in this study.Abbreviations: L -length (mm); W -width (mm); L/W -length/width ratio; R -branching position of vein R / tegmen length; M -branching position of vein M / tegmen length; CuAbranching position of vein CuA / tegmen length.Remarks.Based on the tegminal venation, this new species can be distinguished from other species within the An thoscytina in having an extremely short cross vein mcua.This new species is similar to A. aphthosa in having cross veins ir, rm, and mcua extremely close to wing apex, but the new species is much larger in size and has a tegmen with vein M two-branched.

(Figs 3-5)
Etymology.The specific epithet is derived from the Latin "ele gans" (meaning elegant), and refers to this species' beautiful shape.
Paratypes.STMN48-1788, sex unknown, adult in lateral aspect with tegmen and hind wing preserved; STMN48-1789, sex unknown, adult in lateral aspect with tegmen preserved; STMN48-1790, adult male in lateral aspect with tegmen preserved; STMN48-1791, adult male in lateral aspect with tegmen preserved; STMN48-1792, sex unknown, adult in lateral aspect with tegmen preserved; STMN48-1793, adult male in lateral aspect with tegmen preserved; STMN48-1794, adult male in lateral aspect with tegmen preserved; STMN48-1795, sex unknown,   4A, B, 5).Postclypeus swollen, about 3.0 mm long, with oblique grooves and a distinct median groove.Compound eyes large, nearly round (Figs 3,5A).Antennal length about 0.8 mm; scape and pedicel thick; flagellum aristiform, with segments invisible (Figs 3B, D).Pronotum well-developed, with width about 3.0 mm.Fore femur extremely strong, about 2.5 mm long and nearly 1.0 mm wide; fore tibia about 3.0 mm long, fore tarsus about 1.5 mm long, with three tarsomeres; basitarsomere very short; apical tarsomere longer than mid tarsomere; two claws and an arolium visible ( Figs 4B, D, 5C, E).Middle femur and tibia almost as long as fore femur and tibia respectively; middle femur slenderer than fore femur; middle tarsus slight shorter than fore tarsus, with three tarsomeres; apical tarsomere longer than mid tarsomere and basitarsomere; two claws and an arolium visible (Figs 5C, E).Hind tibia slender, with a short lateral spine on basal 2/3 of its length and two rows of tiny teeth apically; hind tarsus about 2.0 mm long, with three tarsomeres visible; basitarsomere and mid tarsomere of similar shape, and with a row of tiny apical denticles (Figs 5C-E).Male genitalia well-developed; sclerotized genital plate visible in lateral view; anal tube elongate, strongly curved (Figs 5A, D, E).Ovipositor short, just extending beyond pygofer, slightly curved upwards (Fig 5F).
Tegmen broad, 20.4-23.2mm long and 7.3-8.6mm wide, with length/width ratio from 2.6 to 2.9 (Figs 3, 4A, B, 5; Table 1).Tegmen with dark and irregular patches (Figs 3, 4A, B, 5A).Costal margin slightly arched.Posterior margin of basal 1/6 wing length curved and then recurving at the ending of vein CuP.Apical margin rounded.Pc+CP running to costal margin and ScP running to and fusing with R+M+CuA.ScP+R bifurcating into ScP+RA and RP at about basal 0.3 wing length.RA simple, separating from ScP+RA, and then connected with RP by cross vein ir.RP simple, almost straight, connected with M 1+2 by cross vein rm just distal of junction with cross vein ir.Stem M subparallel to RP, and branching into M 1+2 and M 3+4 near basal 0.7 wing length.M 1+2 nearly as long as MP.Cross vein mcua basal of or at the same level as cross vein rm.Stem CuA bifurcating into CuA 1 and CuA 2 in basal 2/3 of wing length.CuA 1 two to three times as long as CuA 2 .CuA connected to CuP by long cross vein cuacup at departure from M+CuA.CuP long and straight.A 1 nearly straight, slightly curved apically.A 2 short, oblique.
Hind wing partly preserved (Figs 4A, C).RA curved apically.RP long, curved just beyond junction with cross vein rm.Stem M nearly straight, subparallel to RP, and twobranched.M 1+2 sinuous, curved at junction with cross vein rm.Stem CuA slightly curved, two-branched.CuA 1 connected with M by cross vein mcua just beyond departure from CuA and then straight.CuA 2 sinuous.
Remarks.Anthoscytina elegans Chen, Wang & Zhang, sp.n. is very much bigger than the other species in the genus Anthoscytina.This new species resembles A. brevi neura Chen, Wang & Zhang, sp.n., which is similar in size, venation patterns on tegmen and hind wing, and other body structures, but they differ in the length of cross vein mcua, the branching position of stem M and colour patterns on tegmen.

DISCUSSION
There is considerable intra-specific or even intra-individual variation in the venation of some procercopids (e.g., Ansorge, 1996;Ren et al., 1998).Both of the two new species reported herein were discovered in the same horizon at the same locality (Jiulongshan Formation in Daohugou Village), are similar in size, tegminal venation and other body structures (Figs 1 and 2; Table 1), which indicates a close relationship.However, there are also some stable differences in venation and the colour patterns on the tegmen, which confirm that they are independent biological species.In addition, both species are represented by both male and female specimens, which exclude the possibility that the morphological variation is sexual dimorphism.
To date, thirteen species are assigned to Anthoscytina (Becker-Migdisova, 1949;Hong, 1983Hong, , 1986;;Shcherbakov, 1988;Ren, 1995;Ren et al., 1998;Li et al., 2013;Hu et al., 2014;Chen D. et al., 2015; this study), making it the largest genus of Procercopidae.These species are known from the Early Jurassic to Early Cretaceous in Russia, Central Asia and China, and show an extremely high diversity in tegminal venation as well as other body structures, indicating that this large genus is possibly the result of a poorly defined combination of characters, which might not validly reflect a natural subdivision (i.e., a polyphyletic group).Ren et al. (1998) erected Anthoscytina aphthosa based on several compression fossils from the Lower Cretaceous in northern China, and the species is very special in having tegmen and hind wing with vein M simple (vs.tegmen with M with at least two branches and hind wing with M two-branched in other procercopids).Anthoscytina macula Hu, Yao & Ren, 2014, collected from contemporaneous strata at a nearby locality, is very similar to A. aphthosa in having similar wing venation.Chen D. et al. (2015) report a new procercopid with vein M on tegmen and hind wing simple on the basis of one fossil specimen collected at the same locality as A. aphthosa, but put this species into a new genus Stellularis.The unusual wing venation suggests that these three species are obviously different from the type species of Anthoscytina, and A. aphthosa and A. macula, and should be transferred to the genus Stellularis.
Li et al. ( 2013) report a pair of copulating procercopids, and erected a new species Anthoscytina perpetua.The abundant fossil material described by Li et al. (2013) indicate that the ovipositor of A. perpetua is short, not exceeding anal tube. A. daica Shcherbakov, 1988, A. brevineura Chen, Wang & Zhang, sp. n.;and A. elegans Chen, Wang & Zhang, sp. n. also have short ovipositors.However, the ovipositors of A. aphthosa and S. longirostris are extremely long, exceeding the tip of the tegmina (Ren et al., 1998;Chen D. et al., 2015).This difference in the length of the ovipositors further confirms that Anthoscytina and Stellu laris are two independent genera and A. aphthosa and A. macula should be transferred to Stellularis.
The family Procercopidae is widely accepted as the stem group of cercopiods, which includes the ancestors of modern Cercopoidea (Shcherbakov & Popov, 2002;Wang et al., 2012).Tegmen and hind wing with vein M unbranched are apomorphic characters for extant cercopoids.These characters are also shared by Stellularis from the Early Cretaceous in Northeastern China (Ren et al., 1998;Hu et al., 2014;Chen D. et al., 2015), suggesting that this genus possibly represents a transitional form between Procercopidae and recent Cercopoidea.By the mid-Creaceous, the remaining procercopids became extinct and modern cercopoids (Aphrophoridae and Cercopidae) appeared (Shcherbakov & Popov, 2002).
Zhang, nom.n.; A. brevineura Chen, Wang & Zhang, sp.n.; and A. elegans Chen, Wang & Zhang, sp.n.Revised diagnosis.Fore femur robust, hind tibia long and slender, with a short lateral spine; Ovipositor short; tegmen with vein R bifurcating near basal 1/3 wing length; RA simple or multi-branched; RP simple; M with at most 3 branches; CuA branching basal of or at the same level as the branch in M; cross vein im absent; hind wing with vein RA and RP simple, M and CuA two-branched.
is similar to A. daica and A. parallelica in having a tegmen with a multi-branched R and differs in its M 1+2 and M 3+4 are longitudinal and nearly parallel.Anthoscytina brevineura Chen, Wang & Zhang, sp.n. (Figs 1, 2)