Phylogeny of split-footed lacewings (Neuroptera, Nymphidae), with descriptions of new Cretaceous fossil species from China

Transcription

1 Cladistics Cladistics 31 (2015) /cla Phylogeny of split-footed lacewings (Neuroptera, Nymphidae), with descriptions of new Cretaceous fossil species from China Chaofan Shi a,b, Shaun L. Winterton c and Dong Ren b,* a School of Earth Science and Geological Engineering, Sun Yat-sen University, Guangzhou , China; b College of Life Sciences, Capital Normal University, 105 Xisanhuanbeilu, Haidian District, Beijing , China; c California State Arthropod Collection, California Department of Food and Agriculture, Sacramento, CA 95832, USA Accepted 27 October 2014 Abstract A phylogeny of the lacewing family Nymphidae based on morphology and DNA sequences is presented including representatives of all living genera and selected fossil genera. Widely distributed Jurassic and Cretaceous genera gave rise to recent taxa now restricted to Australasia. Two previously defined clades (i.e. Nymphinae and Myiodactylinae) were recovered and reflect the diverging adult and larval morphology of members of these two subfamilies. From Chinese Cretaceous deposits, a new genus (Spilonymphes gen. nov.) is described with one new species, as well as new species described in the genera Baissoleon Makarkin and Sialium Westwood The Authors Cladistics published by John Wiley & Sons Ltd on behalf of Willi Hennig Society. Nymphidae are a small family of distinctive neuropterans characterized by a medially divided arolium, leading to their common name of split-footed lacewings. The family is considered one of the more plesiomorphic clades of Myrmeleontiformia, sister to a group comprising at least Myrmeleontidae (antlions) and Ascalaphidae (owlflies) (Asp ock et al., 2001, 2012; Asp ock, 2002; Engel and Grimaldi, 2008) or also including Nemopteridae (spoon-winged lacewings) (New, 1984; Oswald, 1998; Winterton et al., 2010). Extant Nymphidae are restricted entirely to the Australasian region, the greatest diversity being found in eastern mainland Australia with a few species found in western Australia and New Guinea (New, 1987). A single species has been described from the Philippines (i.e. Myiodactylus chrysopoides Navas) but the type has been lost and no specimens are known to confirm this anomalous record (New, 1981). Eight extant genera containing 33 species are described with an additional 14 extinct genera containing 23 species, from both Mesozoic and Palaeogene deposits. *Corresponding author: address: rendong@mail.cnu.edu.cn Diagnostic features of nymphid imagos include elongated filiform antennae, ocelli absent, legs with a bifid arolium, wings with trichosors present, nygmata absent and thyridiate (incomplete) crossveins present of varying length along the subcostal space. Nymphidae are one of the few families of lacewings that lay eggs on silken stalks (New, 1982, 1983a). Arguably, the most specialized arrangement of eggs on silken stalks found in Neuroptera is produced by the relatively derived genus Nymphes Leach. Eggs are laid with every second egg produced with a silken stalk, and intermediate eggs produced perpendicular to the previous one and used to connect the stalked eggs such that the egg mass is arranged in a large U -shaped pattern. Immature stages are distinctive and are known for the genera Osmylops Banks, Nymphes and Norfolius Navas (New, 1982, 1983a, 1989a; New and Lambkin, 1989). Immatures typically have a large armoured head with six stemmata and broadly separated jaws that often articulate beyond 180 (Mac- Leod, 1964). The jaw has a large single tooth midway along its length, separating it from most other neuropteran larvae. Antennae are shorter than half the length of the mandible with the flagellum being distinctly 2015 The Authors Cladistics published by John Wiley & Sons Ltd on behalf of Willi Hennig Society This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

2 456 C. Shi et al. / Cladistics 31 (2015) thinner than the scape and pedicel. Labial palpi have three segments and scoli are present along the lateral edges of the mesothorax, metathorax, and abdomen. New (1984) discussed the intrafamilial relationships and biogeography of Nymphidae. Two major types of nymphids have been defined previously, nymphoid and myiodactyloid, which have been elevated to family-level status by some authors (Handlirsch, ; Tillyard, 1926). By contrast, some authors considered this a simple issue of rank, with the clades treated as sister groups. Handlirsch ( ), for example, considered Myiodactylidae to be more distantly related to Myrmeleontiformia, most typically in a clade with Osmylidae. As reviewed by New (1981), Myiodactylidae was proposed by Handlirsch ( ), and followed by various authors (e.g. Esben-Petersen, 1914; Comstock, 1918; Navas, 1921; Withycombe, 1925; Tillyard, 1926). Although Handlirsch ( ) did not provide a diagnosis or list of included genera for the family, the family name Myiodactylidae was used in the discussion of neuropteran familial relationships; no earlier references have been found mentioning Myiodactylidae. Myiodactylidae is considered synonymous with Nymphidae here, although the two names reflect the notable dichotomy of adult and larval body form found in the family in a broad sense, and reflected in the subfamilial rankings followed herein (i.e. Nymphinae and Myiodactylinae). Nymphinae adults typically have elongated wings, tibial spurs present, brown to orange body coloration, and male genitalia with gonarcus arms widely separated medially. This group includes the genera Nesydrion Gerstaecker, Austronymphes Esben-Petersen and Nymphes Leach (Fig. 1a, b). Nymphinae larvae are typically brownish, with a relatively elongated body, short thoracic and abdominal scoli, and usually carry a large trash packet; these larvae inhabit leaf litter and soil. In contrast, adults of Myiodactylinae are typified by broader, rounded wings, lack of tibial spurs, frequent green body coloration and the male gonarcus ends very close or touching medially. Genera in this subfamily include the remaining extant genera, Osmylops Banks, Myiodactylus Brauer, Norfolius Navas, Umbranymphes New and Nymphydrion Banks (Fig. 1c, d) (New, 1984, 1987). Myiodactylinae larvae also have a typically greenish body colour, with a flattened discoid body shape with elongated scoli and little to no trash packet; these larvae are arboreal (New, 1982, 1983a, 1989a), although New and Lambkin (1989) described the larva of Norfolius as a litter dweller. (c) (d) Fig. 1. Living Nymphidae. Nymphes nigrescens New, Western Australia (photo: Fred and Jean Hort); Nymphes myrmeleonoides Leach, Queensland (photo: Shaun L. Winterton); (c) Norfolius howensis (Tillyard), Queensland (photo: Shaun L. Winterton); (d) Myiodactylus osmyloides Brauer, Queensland (photo: Shaun L. Winterton).

3 C. Shi et al. / Cladistics 31 (2015) The earliest fossil nymphids are recorded from Jurassic deposits that correspond very well with the proposed origin of the family based on DNA sequence divergence estimates by Winterton et al. (2010). Four genera with six species have been described from localities in China, Kazakhstan and Germany (Makarkin et al., 2013b; Shi et al., 2013). Nymphidae were apparently more diverse and widely distributed during the Cretaceous. To date, ten genera with 14 species have been described from the Cretaceous of England, Russia, Myanmar, Brazil and China, including the new genus and species described herein. They were from the Jehol Biota in China, which was a diverse fauna in Early Cretaceous inclusive of abundant and remarkable insects (Ren, 1998; Ren et al., 2010; Gao et al., 2013; Yao et al., 2014). Besides, three species of Nymphidae from the Eocene have been described. One species from the Early Eocene of USA belongs to the extant genus Nymphes, which is the earliest representative of any extant genus (Archibald et al., 2009). The other two species are described from Baltic amber, belonging to the genus Pronymphes Kr uger (Hagen, 1854, 1856; Kr uger, 1923; Archibald et al., 2009). A phylogeny of Nymphidae is presented herein based on morphological scoring of all extant species plus a selection of relatively complete fossil exemplars, and combined with DNA sequence data for a subset of extant species. The long held concept of a basal dichotomy of living nymphids is tested, confirming two subfamilies Nymphinae and Myiodactylinae, and the placement of various fossil genera (including new genera described herein) is investigated relative to the total evidence phylogeny. Materials and methods Terminology Wing venation terminology used here generally follows New (1981) except for indication of MA, MP1 and MP2 on the hind wing (Fig. 2). The corresponding venation is indicated with colour coding in Fig. 2: 1A 3A, analis (brown); CuA, cubital anterior (magenta); CuP, cubital posterior (purple); MA, medial anterior (blue); MP, medial posterior (pink); MP1, anterior branch of MP (yellow); MP2, posterior branch of MP (orange); R1, radial anterior; Rs, radial sector (green); rv, recurrent humeral veinlet; Sc, subcosta. Wing venation terminology in Nymphidae has been treated in two ways in previous work by New (1981) and Oswald (1997). The main difference is the homology statement and delineation of MA in the forewing, essentially whether or not MA is assumed as fused with Rs/R basally. New (1981) identified forewing MA as shown in Fig. 2 (blue vein), while Oswald Fig. 2. Wing venation terminology. Forewings and hind wings of: Norfolius howensis (Tillyard); Austronymphes insularis Esben- Petersen. Major wing veins are highlighted in colour: radial sector (Rs): green; medial anterior (MA): blue; medial posterior (MP): pink; anterior branch of MP (MP1): yellow; posterior branch of MP (MP2): orange; cubital anterior (CuA): magenta; cubital posterior (CuP): purple; analis (1A, 2A, 3A): brown. Inset shows detail of thyridiate crossveins in Sc space. (1997) treated MP1 (yellow) as MA and MP2 (orange) as MP. The obvious sigmoid vein in the hind wings of many Neuroptera indicates that MA fused with Rs/R basally, as identified by various authors in studies on Plega signata (Hagen) (Mantispidae; Ferris, 1940: fig. 15B), Wesmaelius concinnus (Stephens) (Hemerobiidae; Oswald, 1993b: fig. 51) and Dilar saldubensis Navas (Dilaridae; Asp ock et al., 1980: fig. 423; Shi et al., 2012: fig. 5), and exemplified by the oblique vein in the forewing (and hind wing) of Norfolius howensis (Tillyard) (Nymphidae; Figs 2b and 3e), Dilar saldubensis Navas (Dilaridae; Asp ock et al., 1980: fig. 423; Shi et al., 2012: fig. 5) and Osmylidae (New, 1983b:

4 458 C. Shi et al. / Cladistics 31 (2015) (c) (d) (e) (f) Fig. 3. Nymphidae wings. Austronymphes insularis Esben-Petersen (forewing length (FWL) = 20.5 mm); Nesydrion fuscum Gerstaecker (FWL = 27.4 mm); (c) Myiodactylus osmyloides Brauer (FWL = 21.3 mm); (d) Osmylops sejunctus (Walker) (FWL = 23.4 mm); (e) Norfolius howensis (Tillyard) (FWL = 23.2 mm); (f) Nymphes myrmeleonoides Leach (FWL = 38.8 mm). figs 1 and 2). They are typically present on forewings and hind wings in many families of Neuroptera, which provides sufficient evidence to suggest that MA basally fused with Rs/R on both forewing and hind wings and is the plesiomorphic condition within the order. The hind wing venational terminology used in this study is also different from that used by Shi et al. (2012: fig. 7D). Shi et al. (2012) suggested MP2 (orange vein in Fig. 2) as MP2 + CuA, and CuA (magenta) as CuP. Examination of hind wing base of Nymphidae displays coalescence of MP1 and MP2, and coalescence of CuA and CuP, which suggests MP2 and CuA in the hind wing are not fused. Genitalic terminology generally follows New (1981) and Oswald (1998), as shown in Fig. 21a. The mediuncus defined here (green) was inferred as the arcessus by New (1981), and 11th gonostyli by Asp ock and Asp ock (2008). The gonarcus (magenta) here is equivalent to the 11th gonocoxite of Asp ock and Asp ock (2008). The paramere (dark blue) is equivalent to the 9th gonocoxite of Oswald (1998) and Asp ock and Asp ock (2008). The gonapsis (light blue) here is

5 C. Shi et al. / Cladistics 31 (2015) equivalent to the 10th gonostyli of Asp ock and Asp ock (2008). Genitalia were macerated in 10% KOH to remove soft tissue, then rinsed in distilled water and dilute glacial acetic acid, and dissected in 80% ethanol. The genitalia preparation was placed in glycerine in a genitalia vial mounted on the pin beneath the specimen. Exemplar selection Nymphidae have an extensive fossil record (23 species in 14 genera) comparable to the number of extant taxa (33 species in eight genera) (Appendix 1). While all living genera are restricted to the Australasian region, extinct representatives of the family have been found far more widely, being recorded from deposits in China, Russia, Kazakhstan, Germany, England, Myanmar, USA and Brazil (Makarkin et al., 2013b). No fossil Nymphidae are recorded from anywhere in the extant distribution of the family in Australia northwards into New Guinea. Nymphidae are relatively rare lacewings and are uncommon in collections, although one species of Nymphes (N. myrmeleonoides Leach) can be locally abundant in dry sclerophyll forests with sufficiently dense understorey, and is also known to enter houses frequently. All extant genera were included in the morphological analysis by at least one species. These included the genera Osmylops (four species) (Fig. 3d), Myiodactylus (two species) (Fig. 3c), Norfolius (one species) (Fig. 3e), Nesydrion (three species) (Fig. 3b), Austronymphes (one species) (Fig. 3a), Nymphes (three species) (Fig. 3f), Umbranymphes (one species) and Nymphydrion (one species). Umbranymphes is known from only the type specimen and was scored from the literature. DNA nucleotide sequences are known for four species of Nymphidae, having been included previously in analyses of Neuropterida phylogeny by Winterton et al. (2010). Sequences of two ribosomal genes (16S rrna and 18S rrna) and two protein-encoding genes [cytochrome oxidase I (COI) and the CPSase region of carbamoyl-phosphate synthetase-aspartate transcarbamoylase-dihydroorotase (CAD)] were retrieved from GenBank for Nymphes myrmeleonoides Leach (EU734884, EU839751, EU815268, EU860137), Osmylops armatus (McLachlan) (EU734886, EU839754, EU815270, EU860140), Myiodactylus osmyloides Brauer (EU734873, EU839741, EU815255, EU860126) and Norfolius howensis (Tillyard) (EU734882, EU839749, EU815264, EU860134), and were all included in the combined analysis along with sequences for all outgroup taxa. Additional extinct genera were also included in the analysis and selected according to relative completeness of the specimen and the resultant proportion of missing characters in the morphological character matrix (i.e. those with more observable characters were preferentially included in the analysis). These included Liminympha makarkini Ren et Engel (Middle Jurassic, China), Baissoleon similis sp. nov. (Early Cretaceous, China), Baissoleon cretaceous Makarkin (Early Cretaceous, Russia), Nymphites bimaculatus Shi, Makarkin et Ren (Middle Jurassic, China), Sialium sinicus sp. nov. (Early Cretaceous, China), Sialium minor sp. nov. (Early Cretaceous, China) and Spilonymphes major gen. et sp. nov. (Early Cretaceous, China). Outgroups were included from lacewing families Ithonidae (Ithone fulva Tillyard) (EU734865, EU839734, EU815247, EU860118) and closely related families also in Myrmeleontiformia, i.e. Psychopsidae (Psychopsis barnardi Tillyard) (EU734897, EU839764, EU815280, EU860149) and Nemopteridae (Nemoptera coa (Linnaeus) (EU734878, EU839745, EU815259, EU860131) and Chasmoptera hutti (Westwood) (EU734851, EU839723, EU815232, EU860106)). Outgroups were selected based on the most recent phylogenetic analyses of lacewing higherlevel phylogeny by Winterton et al. (2010), and chosen as a mix of the two closest related familes of Myrmeleontiformia (Psychopsidae and Nemopteridae) with a more distantly related family Ithonidae, a group still closely related to Myrmeleontiformia. These families were preferentially selected not only due to their close phylogenetic relationship to Nymphidae, but also because they exhibit numerous putative plesiomorphic character conditions in their wing venation and terminalia. Such features are highly modified or highly reduced in other potential candidate outgroups such as Ascalaphidae, Myrmeleontidae and Chrysopidae, thereby obscuring likely homology and weakening any homology statements proposed here. Morphological examination Sixty-eight adult and larval characters were numerically coded for the four outgroup and 23 ingroup taxa. Morphological characters used in the phylogenetic analysis are listed in Appendix 2. Thirty-nine characters were coded as binary and 29 as multistate. Inapplicable and unknown characters were respectively coded as - and?. The data matrix is given in Supporting Information Tables S1 and S2. Sequence alignment and phylogenetic analysis Sequences were aligned manually, with CAD and COI aligned with reference to translated amino acid sequences (standard eukaryote and invertebrate mitochondrial sequences, respectively) using Mesquite (ver. 2.75) (Maddison and Maddison, 2011). Ambiguously aligned regions of 16S, where positional homology could not be inferred with a reasonable level of confidence, were excluded prior to analysis. Parsimony analyses were conducted using WinClada ver

6 460 C. Shi et al. / Cladistics 31 (2015) (Nixon, 2002) and NONA ver. 2.0 (Goloboff, 1993; Goloboff et al., 2003, 2008), using a branch and bound search protocol to find all trees. All characters were treated as unordered and with equal weight. Bootstrap support values were determined using PAUP*4.0b10 (Swofford, 1999) calculated from 1000 heuristic search (TBR) pseudoreplicates of re-sampled data sets, each with 30 random additions (constant characters excluded). Character states were mapped on a most parsimonious tree (MPT) using WinClada ver. 1.0 (Nixon, 2002), showing only unambiguous changes. Bayesian analyses were performed using MrBayes (Ronquist and Huelsenbeck, 2003). The data were partitioned by data type (DNA sequence, morphology), by locus, and by the remaining two codon positions for each protein-coding locus. A separate GTR + c nucleotide substitution model was applied to each DNA partition. The mk1 model (Lewis, 2001), with coding set to variable, was applied to the morphology partition. Each analysis consisted of four Monte Carlo Markov chains run simultaneously for ten million generations, until stationarity was reached. Trees were sampled every 1000th generation. The first three million trees were discarded as burn-in. A majority rule consensus tree was computed with posterior probabilities (PP) for each node. Results Phylogeny Parsimony analysis of the morphological matrix containing 68 characters across all extant Nymphidae recovered a single MPT [length = 213; consistency index (CI) = 0.52; retention index (RI) = 0.65] (Fig. 4). When DNA sequence data for a select few ingroup and all outgroup taxa were combined with the morphological scoring, it returned a single MPT of identical topology to the tree based on morphology alone but with notable increase in the consistency index (length = 1180; CI = 0.73; RI = 0.63). The tree recovered from the Bayesian analysis was overall congruent in topology, but failed to recover some terminal nodes in Nymphidae, particularly in Myiodactylinae. Support values for bootstrap (BS), Bayesian PP (for congruent Fig. 4. Phylogeny of living Nymphidae. Single tree recovered from parsimony analyses of morphological characters alone (length = 213; CI = 0.52; RI = 0.65), and from combined analysis with DNA sequence data (length = 1180; CI = 0.73; RI = 0.63). Character state changes are plotted on each node, as well as subtended by statistical support values (Bootstrap: Bayesian posterior probability: Bremer support). Bayesian posterior probability values are included only on congruent nodes, as the Bayes tree lacked some resolution in some terminal nodes. Nymphinae and Myiodactylinae are clearly recovered. Images of representative adults and larvae are included. Image credits: larval drawings: CSIRO; photographs: Nymphes nigriscens (Fred and Jean Hort), Osmylops sp. (Anne Marie McKinnon).

7 C. Shi et al. / Cladistics 31 (2015) branches) and Bremer support (B) are plotted on individual nodes in Fig. 4. Nymphidae were recovered as strongly monophyletic (BS: 98; PP: 98; B: 6) and were supported in this analysis by multiple apomorphic characters, including a bifid arolium (character 5: state 1) and wing subcostal thyridiate crossveins present (15:1 3) in the adult, and larval characters such as stemmata number (62:2), antennal flagellum shape (65:1), number of segments of the labial palp (66:1), a single large tooth on the jaw (67:1), and presence of thoracic and abdominal scoli (68:1). One or more of the larval apomorphies defined here are found in some species of Ascalaphidae or Myrmeleontidae (e.g. abdominal and thoracic scoli), but in combination they are clearly unique to Nymphidae. Within Nymphidae there was a distinctive basal dichotomy separating the two defined subfamilies, i.e. Nymphinae and Myiodactylinae. Nymphinae comprises the extant genera Nesydrion, Austronymphes and Nymphes and was recovered with moderate statistical support (BS: 73; PP: 84; B: 2) with Nesydrion sister to the clade Austronymphes + Nymphes. Characters supporting the monophyly of this lineage include the presence of tibial spurs (3:1), narrow costal space (10:2), many rows of crossveins between forewing CuA branches (24:0), 1A short (30:1), hind wing MP branches with multiple rows of linking crossveins (35:1) and, in the male genitalia, lateral lobes on the mediuncus (43:1) and the gonarcus arms separated medially (49:1). Austronymphes is a monotypic genus, while the monophyly of both Nymphes and Nesydrion was relatively well supported. Myiodactylinae was recovered with moderate statistical support (PP: 70; B: 2) and consists of the extant genera Umbranymphes, Osmylops, Norfolius, Nymphydrion and Myiodactylus. Characters supporting the monophyly of this lineage include the absence of tibial spurs (3:0), broad costal space (10:0 1), no crossveins present between forewing CuA branches (24:2), 1A long (30:0), hind wing MP branches with a few linking crossveins (35:0), absence of mediuncus lateral lobes (43:0) and gonarcus dorsal apical touching or very close (49:0). Umbranymphes is a monotypic genus and was recovered as sister-group of the other genera. Osmylops was recovered as paraphyletic. This genus was previously divided into two species groups: the sejunctus species group and armatus species group (Oswald, 1997). The monophyly of the sejunctus species group was well supported, while the armatus species group was recovered as paraphyletic. Norfolius and Nymphydrion are monotypic and were recovered as sister groups. The monophyly of Myiodactylus was relatively well supported. While there is strong support for many of the nodes on the single tree recovered from the analyses of extant species, inclusion of fossil exemplars and the associated increase in missing data in the analysis significantly weakened the statistical support for most nodes, with resultant loss of resolution across the phylogeny. Still, a very similar topology was recovered for the phylogeny when fossil taxa were included (Fig. 5). Of note was the placement of the Jurassic genus Liminympha as sister to all other nymphids, and a subsequent basal dichotomy of Nymphinae and Myiodactylinae. Myiodactylinae was recovered as monophyletic with Spilonymphes in a sister group relationship with Umbranymphes as the sister to the remaining genera in the clade. All other fossil taxa included in the analysis were placed in Nymphinae, with Baissoleon recovered as an intermediate group between Nesydrion and more derived genera. Sialium formed a clade with Nymphites, but was rendered paraphyletic by the latter. Taxonomy Family Nymphidae Rambur, 1842 Type species: Nymphes myrmeleonoides Leach, 1814 Nymphides Rambur 1842; type genus: Nymphes Leach, Nymphitidae Handlirsch ; type genus: Nymphites Haase, Nymphesidae Handlirsch ; type genus: Nymphes Leach, Myiodactylidae Handlirsch ; type genus: Myiodactylus Brauer, Diagnosis. Medium to large lacewings; antennal flagellum elongate, filiform; ocelli absent; prothorax slender, usually longer than wide; arolium bifid; trichosors present; nygmata absent; ScA bulge present; Sc and R1 fused before termination; subcostal area with thyridiate (incomplete) crossveins present and of varying length, true crossveins rarely present (if so, then only basally); larva with myrmeleontoid body form, with narrow filiform antenna; single tooth on jaw; scoli present; six stemmata; egg produced on silken stalk with oviruptor present. Comments. A character apparently unique among Neuroptera, and a putative synapomorphy for the family, is the presence of thyridiate crossveins in the wing subcostal cell (Fig. 6; sensu Oswald, 1998). In our examination, they are present in all extant nymphids and always originate on Sc regardless of length and number. The basal one or two subcostal crossvein(s) are complete or elongated thyridiate (thus appearing complete). The remaining are thyridiate of varying length, ranging from nearly complete with radial end adjacent to R1 (Fig. 6a), to short barely noticeable remnants arising from Sc (Fig. 6c). The length of thyridiate crossveins is variable even within

8 462 C. Shi et al. / Cladistics 31 (2015) Fig. 5. Phylogeny of living and extinct Nymphidae. Single tree recovered from parsimony analyses of combined analysis with morphological characters and DNA sequence data. Character state changes are plotted on each node with Bootstrap support values (> 60%). genera. This structure was mentioned by New (1981, 1984) and drawn by Oswald (1997, 1998). The most common condition for thyridiate crossveins throughout the family is medium length, although in both Nymphinae and Myiodactylinae the sister taxon to the remaining taxa in each clade has medium length. In intermediate and derived genera in each subfamily there is a progressive shortening of the length of the thyridiate crossveins so that they may be barely evident (e.g. Myiodactylinae: Norfolius, Nymphydrion; Nymphinae: Nymphes). In Nymphes and Nesydrion the length and number of thyridiate crossveins can be highly variable among species, from very few short crossveins to numerous very long crossveins. A vein-like structure was observed in the basalmost portion of the costal area on both forewing and hind wing of all extant nymphids and Ithone Newman

9 C. Shi et al. / Cladistics 31 (2015) (c) Fig. 6. Forewing subcostal area, thyridiate crossvein arrangement in Nymphidae. Nymphes myrmeleonoides Leach; Osmylops armatus (McLachlan); (c) Osmylops sejunctus (Walker). Scale bar = 1 mm. (Ithonidae) (Fig. 7). There are three possible terminologies for this structure: ScA, indicating it as a branch of the longitudinal vein Sc, as used in Makarkin et al. (2013b); recurrent humeral veinlet, indicating it as a crossvein in costal area, e.g. in Psychopsidae and Ithonidae (e.g. Winterton and Makarkin, 2010); and ScA bulge (Kukalova-Peck and Lawrence, 2004), indicating membranous thickenings. In this study, we prefer to use the terminology ScA bulge, although the structure actually lacks the bulgelike, oval shape and broad size as drawn in figs 5 and 6 in Kukalova-Peck and Lawrence (2004). In our examination, it is as thin as or slightly wider than actual crossvein/longitudinal veins, but fainter, without setae, and sometimes the same colour as the costal crossveins. On the hind wing, it is sometimes weakly connected with Sc. Both the ScA bulge and the recurrent humeral veinlet are present in Ithone (Fig. 7), while the recurrent humeral veinlets were not clearly indicated in figs 5 and 6 by Kukalova-Peck and Lawrence (2004), and in Daonymphes (Makarkin et al., 2013b: fig. 6A) it is not a recurrent veinlet. Due to the weak connection between ScA bulge and Sc in the hind wing, we prefer not to use ScA for this structure. New (1981, 1984) mentioned Myiodactylidae as being first proposed by Handlirsch ( ), although Handlirsch only mentioned Myiodactylidae twice, once in a discussion of relationships among several families, and then in a checklist. Various subsequent authors (e.g. Esben-Petersen, 1914; Comstock, 1918; Navas, 1921; Withycombe, 1925; Tillyard, 1926) have used Myiodactylidae, and none attributes the concept to any author earlier than Handlirsch ( ). Included genera (see Appendix 1 for a checklist of species). Liminympha Ren et Engel, 2007, Daonymphes Makarkin, Yang, Shi et Ren, 2013, Nymphites Haase, 1890, Mesonymphes Carpenter, 1929, Sialium Westwood, 1854, Cretonymphes Ponomarenko, 1992, Baissoleon Makarkin, 1990a, Olindanymphes Martins- Neto, 2005, Santananymphes Martins-Neto, 2005, Araripenymphes Menon, Martins-Neto et Martill, 2005, Spilonymphes gen. nov., Elenchonymphes Engel et Grimaldi, 2008, Dactylomyius Makarkin, 1990b, Pronymphes Kr uger, 1923, Austronymphes Esben- Petersen, 1914, Myiodactylus Brauer, 1866, Nesydrion Gerstaecker, 1885, Norfolius Navas, 1922, Nymphes Leach, 1814, Nymphydrion Banks, 1913, Osmylops Banks, 1913, Umbranymphes New, Key to genera of extant Nymphidae (modified after New, 1981, 1987) 1 Short tibial spurs present on at least hind tibia; forewing costal margin narrower; body colour usually brown to orange in live specimen Tibial spurs absent; forewing typically with broad costal margin; body colour frequently green in live specimen Forewing with veins 2A and 3A forming a large closed loop (Figs 2b and 3a) Austronymphes Esben-Petersen. Forewing anal veins not forming closed loop Hind wing with two rows of cells behind CuA (Fig. 3f)...Nymphes Leach. Hind wing with a single row of cells behind CuA (Fig. 3b) Nesydrion Gerstaecker. 4 Forewing costal cells with veins linking costal crossveins at least in basal half of wing, forming one or more rows of cells (Figs 2a and 3e)...

10 464 C. Shi et al. / Cladistics 31 (2015) (Fig. 3d)...Osmylops Banks. Forewing CuP space broad, typically twice width of intracubital space (except M. osmyloides); forewing MP forked in distal part of wing (level with outer gradate crossveins) appearing simple (Myiodactylus), or forked at base of wing (Nymphydrion); forewing costal space very broad especially at base of wing (Fig. 3c) Forewing MP forked at outer gradate series (appearing simple)...myiodactylus Brauer. Forewing MP forked at base of wing nymphydrion Banks. Subfamily Myiodactylinae Handlirsch, , stat. nov Myiodactylidae Handlirsch [as synonym of Nymphidae Rambur: see New 1984] Myiodactylini Navas 1922; type genus: Myiodactylus Brauer, 1866 Nymphydrini Navas 1922; type genus: Nymphydrion Banks, 1913 Type genus. Myiodactylus Brauer, Diagnosis. Medium to small nymphids; tibial spurs absent; wing costal area broad (often with multiple forked costal crossveins); no crossveins between forewing CuA branches; 1A long; hind wing MP branches with a few linking crossveins; dorsal ends of gonarcus arms close to touching. Fig. 7. Wings of Nymphidae and Ithonidae. Osmylops sejunctus (Walker); Ithone fulva Tillyard. Insets show detail of ScA bulge Forewing costal cells in a single row, usually with pectinate forking (e.g. Fig. 3c) Forewing subcostal space with a single elongated crossvein basally, vein MP forks in basal half of wing; male genitalia with gonapsis present (Fig. 3e) Norfolius Navas. Forewing subcostal space with multiple elongated crossveins along length, vein MP forks in apical half of wing; male genitalia with gonapsis absent umbranymphes New. 6 Forewing CuP space narrow, typically less than 1.5 times width of intracubital space; forewing MP forked at least in basal one-third to basal half of wing; forewing costal space typically narrow Included genera. Umbranymphes New, 1987, Spilonymphes gen. nov., Osmylops Banks, 1913, Norfolius Navas, 1922, Nymphydrion Banks, 1913, Myiodactylus Brauer, Spilonymphes major gen. et sp. nov. Figs 8 and 9 Type species. Spilonymphes major gen. et sp. nov. Etymology. From Greek spilos [rpιkος, m], spot, and Nymphes. Species epithet is from the Latin, magnus, -a, -um (comparative major), great (greater). Diagnosis. Forewing basal rs-m present, proximal to the oblique vein; MA separated from Rs close to the

11 C. Shi et al. / Cladistics 31 (2015) Fig. 8. Photograph and line drawing of Spilonymphes major gen. et sp. nov. Holotype CNU-NEU-LB origin of Rs; CuP space broad, nearly three times as wide as intracubital space; hind wing CuA space broad. Description. Forewing preserved length 22.5 mm, preserved width 6.6 mm. Hind wing preserved length 21.1 mm, preserved width 6.2 mm. Prothorax longer than wide. Pterothorax well developed. Mesothoracic prescutum divided by median notal suture. Wings elongated, with apex pointed. Irregular wing markings present medially, at pterostigma and in distal part. Forewing costal area dilated distal to the pterostigma. Costal crossveins seldom forked and more numerous towards apex. Sc and R1 approximating along length, then fused at approximately distal one-quarter of wing length. Rs separated from R1 near wing base. Seven crossveins present between R1 and Rs. MA separated from Rs stem around the basal one-quarter of wing length. Rs with 17 branches. Outer gradate crossveins and proximal irregular crossveins present among Rs branches. MP forked before the separation of MA from Rs. Basal rs-m present, proximal to the oblique vein. MP1 forked until near wing margin, with few branches. MP2 straight and strong, pectinately branched from the midway of its length, with numerous branches terminating on outer margin. CuA parallel to posterior margin with broad space between them. CuA pectinately branched with four or five branches midway along wing length. CuP space broad, about three times as broad as intracubital space. CuP pectinately branched with about six branches terminating on posterior margin. CuA and CuP branches continuously forked before terminating. 1A long and pectinate forked. 2A and 3A forked. Hind wing shorter than forewing with similar venation pattern, except MP forked from very near wing base, MP2 pectinately branched around midway along wing length with more branches, up to ten. CuA parallel to posterior margin, with broad space between them. CuA pectinately branched with seven branches terminating on posterior margin. CuP long and pectinately branched. CuA and CuP branches continuously forked before terminating. Type material. Holotype CNU-NEU-LB Locality and horizon. Huangbanjigou Village, Chaomidian County, Beipiao City, Liaoning Province, China. Yixian Formation, Early Cretaceous. Comments. The new genus has a forewing costal space slightly broader than typical Nymphinae genera, and is more similar to recent myiodactyline genera. Our analyses place this genus in Myiodactylinae as sister to Umbranymphes. A broad forewing costal space is not common in fossil nymphids and is only found in four monotypic genera (although being somewhat continuous in character it may be difficult to delineate): Spilonymphes gen. nov., Daonymphes Makarkin, Yang, Shi et Ren, Dactylomyius Makarkin, Elenchonymphes Engel and Grimaldi. The new genus has a forewing MP forked proximal to the separation of MA, which is found in all fossil nymphids, and considered as a plesiomorphic character in Nymphidae. Forewing MP is forked distal to the separation of MA in the recent myiodactyline genera.

12 466 C. Shi et al. / Cladistics 31 (2015) (c) (d) Fig. 9. Wing venation of Spilonymphes major gen. et sp. nov. Holotype CNU-NEU-LB Left forewing; right forewing; (c) left hind wing; (d) right hind wing.

13 C. Shi et al. / Cladistics 31 (2015) Spilonymphes gen. nov. differs from Elenchonymphes and Dactylomyius by the denser spaced Rs branches, and MP2 forked in the basal half of wing length on both forewing and hind wing. Elenchonymphes has fewer Rs branches and MP2 forked in distal half of wing length in both wings. The hind wing of Dactylomyius has fewer Rs branches, and MP2 forked near wing margin. Moreover, the hind wing of Dactylomyius is distinctly dilated in distal half, while the hind wing of Spilonymphes gen. nov. is elongated and smoothly dilated in the distal half. The new genus resembles Daonymphes most closely, but can be easily distinguished from the latter by forewing MP2 forked in basal half, CuP space nearly three times wide as intracubital space, instead of forewing MP2 forked in the distal half, and the CuP space about twice as wide as intracubital space in Daonymphes. Subfamily Nymphinae Rambur, 1842 Nymphini Navas 1922; type genus: Nymphes Leach, 1814 Type genus. Nymphes Leach, 1814 Diagnosis. Large to medium nymphids; tibial spurs present at least on hind legs; costal area narrow; crossveins present between branches of CuA; 1A short; hind wing MP branches with multiple rows of linking crossveins; male genitalia with arms of gonarcus far separated medially, mediuncus with large lateral lobes. Included genera. Nesydrion Gerstaecker, 1885, Baissoleon Makarkin, 1990a, Sialium Westwood, 1854, Nymphites Haase, 1890, Austronymphes Esben- Petersen, 1914, Nymphes Leach, Baissoleon Makarkin, 1990 Baissoleon Makarkin, 1990a: 125 (Nymphitidae) Makarkin et al., 2012: 57, 65 (Nymphidae) Type species. Baissoleon cretaceous Makarkin, 1990a, by original designation. Revised diagnosis. Prothorax longer than wide; tibial spurs present at least on hind legs; wings slender; pterostigma distinct; Sc + R1 entering margin before wing apex; costal area not dilated after the fusion of Sc and R1; single row of crossveins present between forewing CuA branches; forewing CuP dichotomously forked. Species included. Two Early Cretaceous species, B. cretaceous from Baissa in Transbaikalia (Russia) and B. similis sp. nov. from the Yixian Formation (China). Remarks. Baissoleon shares characters with typical Nymphinae genera, e.g. tibial spurs, elongated wings, and narrow costal area. Yet it differs from these genera by the narrow costal distal area, Sc + R1 entering margin before wing apex and a narrow CuA space. Baissoleon is similar to Nesydrion based on MP forked proximal to the separation of MA. Baissoleon also resembles Nymphes and Austronymphes based on a distinct pterostigma in both wings. Compared with fossil nymphids, Baissoleon and Olindanymphes (from the late Aptian Crato Formation in Brazil) are closely related genera. Besides general similarity of their venation, they share one significant condition in contrast to all other genera, i.e. forewing CuP is non-pectinate. Although in all known Jurassic nymphids CuP is strongly pectinate in the forewing, a non-pectinate condition found in these Cretaceous genera is probably a plesiomorphic condition. A similar configuration of CuA and CuP is characteristic of the Late Jurassic genus Chrysoleonites Martynov, which is thought to be closely related to ancestors of the myrmeleontoid + chrysopoid clades (Yang et al., 2012). Baissoleon similis sp. nov. Figs 10 and 11 Etymology. From Latin similis, -e, similar, in reference to the close resemblance between this species and B. cretaceous. Diagnosis. Very similar to B. cretaceous, but easily distinguished by the longer CuP and 1A (CuP terminating distal to the fork of MP, and 1A terminating nearly at level of fork of MP in B. similis sp. nov.; CuP terminating nearly at level of fork of MP, and 1A terminating much more proximally to the fork of MP in B. cretaceous). Description. Body length (from apex head to abdomen) 15.2 mm. Head elongated. Mandible protruding with apex pointed. Compound eye mediumsized. Antenna appear short (probably incomplete). Prothorax elongated, slightly narrower than head. Mesonotum and metanotum distinctly broader than prothorax. Legs slender, with femora and tibiae quite long. Hind tibia with apical spurs. Abdomen slender, with nine tergites, apical segments dilated. First tergite poorly preserved, short. Second to seventh tergites rather long; eighth to ninth tergites short, transverse. Forewing length 18.2 mm, width 5.2 mm. Costal space narrow. Costal crossveins simple before pterostigma, very shallowly forked distally. Pterostig-

14 468 C. Shi et al. / Cladistics 31 (2015) (c) Fig. 10. (a, b) Photograph and (c) line drawing of Baissoleon similis sp. nov. Holotype CNU-NEU-NN PC. ma well developed. Subcostal space rather narrow, slightly dilated distally. Sc and R1 fused below pterostigma; Sc + R1 entering margin before wing apex. Rs separated at acute angle from R1 near wing base, slightly zigzagged in middle part. R1 space narrower basally and distally, dilated most at middle part; 12 crossveins sparsely distributed before fusion of Sc and R1; hypostigmal cell long. Rs with seven branches; MA separated from Rs stem very far from its origin, nearly at midway of wing length. Most branches of Rs rather shallowly forked, except distal branches having additionally minute forks (dichotomous). Outer gradate series of crossveins complete; several crossveins irregularly arranged proximal to this series between Rs branches (except between three distal-most). MP forked at midway between the origin of Rs and the separation of MA. One oblique vein between Rs stem and M. MP1 slightly arched, pectinately branched distally. MP2 strongly zigzagged; pectinately branched with three branches terminating on outer margin; all branches simple except proximal-most branch in left wing which is rather deeply forked. CuA long, zigzagged, running rather close to posterior margin; pectinately branched with five simple branches; four proximal branches connected by one row of crossveins. CuP short, deeply forked. Four (left wing) to five (right wing) intracubital crossveins. Basal CuP and 1A closely approach or touch. Between CuP and 1A one distal crossvein detected (connecting CuP and anterior branch of 1A fork). 1A long, deeply forked. 2A short, probably simple. 3A short, shallowly forked. Between 1A and 2A, 2A and 3A one crossvein present respectively. Hind wing length 15.3 mm, width ca. 4.5 mm (when restored); smaller than forewings. Costal space somewhat narrower than in forewing. All costal crossveins simple before pterostigma, some forked after pterostigma. Pterostigma distinct. MA separated from Rs stem far from wing base, before midway of wing length. Rs with seven branches, all but one forked (except dichotomous distal-most branches). Outer gradate series of crossveins complete; several crossveins irregularly arranged proximal to this series between Rs branches (except between three distal-most). MP forked at wing base. MP1 long, almost straight, pectinately branched very distally, with two to three simple short branches. MP2 pectinately branched with four to five branches, simple to deeply forked once. Three proximal MP2 branches connected by crossveins. CuA short, pectinately branched, with three branches. CuP short, probably simple. 1A and 2A short, simple. Type material. Holotype CNU-NEU-NN PC, a nearly complete well-preserved specimen, with hind wings strongly crumpled. Type locality and horizon. Liutiaogou Village, Ningcheng County, Chifeng City, Inner Mongolia Autonomous Region, China. Yixian Formation, Early Cretaceous. Sialium Westwood, 1854 Sialium Westwood, 1854: 390, 396 (Neuroptera, allied to Sialis) Geinitz, 1884: 571 (?Orthoptera) Scudder, 1886: 472 (Blattoptera) Geinitz, 1887: 200 (Blattoptera) Scudder, 1891: 130 (Blattoptera)

15 C. Shi et al. / Cladistics 31 (2015) (c) (d) Fig. 11. Wing venation of Baissoleon similis sp. nov. Holotype CNU-NEU-NN PC. Left forewing; right forewing; (c) left hind wing; (d) right hind wing.

16 470 C. Shi et al. / Cladistics 31 (2015) Handlirsch, : 609 (Nymphitidae) Handlirsch, 1939: 159 (Nymphitidae) Martynova, 1949: 167 (Nymphitidae) Lambkin, 1988: 451, 454 (Nymphidae) Whalley, 1988: 46 (Nymphitidae) Jarzembowski, 1993: 178 (Neuroptera) Jepson et al., 2012: 44 (Nymphidae) Type species. Sialium sipylus Westwood, Revised diagnosis. Tibial spurs present at least on hind legs; wings proximally narrow; forewing humeral veinlet recurrent; intracubital space dilated before CuA forked; two or more rows of crossveins present between CuA branches; CuP space broad, nearly twice as wide as basally intracubital space; hind wing MP pectinately branched with more than eight branches; CuP long, pectinately branched with rich branches. Species included. Sialium sipylus Westwood, 1854; Sialium sinicus sp. nov.; Sialium minor sp. nov. Sialium sinicus sp. nov. Figs 12 and 13. Etymology. Latinized name of China. Diagnosis. Wing markings present in subcostal area and whole apical area in both wings, markings sparsely distributed on posterior part of forewing, one large spot present near distal one-third of wing length on hind wing. Description. Head large, wider than long. Compound eye medium sized. Antenna filiform. Prothorax almost as large as head, but longer than wide. Pterothorax larger than prothorax. Legs slender. Hind tibia with a pair of apical spurs. Forewing preserved length 41 mm, preserved width 11.8 mm. Hind wing preserved length 37.5 mm, preserved width 10.5 mm. Wings subequal, elongated. Posterior and outer margins waved. Forewings bearing discontinuous markings in subcostal area, around pterostigma area, in the basal posterior part and apical area. Hind wing bearing discontinuous markings in subcostal area and in distal part, one large spot near distal one-third of wing length. Forewing costal crossveins seldom forked before pterostigma area, and progressively denser with more forks from pterostigma area to termination. Humeral veinlet recurrent. Sc and R1 closely parallel. Rs separated from R1 at basal one-tenth of wing length. MA separated from Rs stem at basal one-fifth of wing length. MP forked between the origin of Rs and the separation of MA. One oblique vein present closely before the fork of MP. MP1 straight and unbranched. MP2 pectinately branched with numerous branches terminating on outer margin. One series of crossveins present among them. MP2 branches continuously forked before termination. Basal mp-cua oblique. CuA and CuP separated below the oblique crossvein. CuA pectinately branched with four branches terminating on the midway of wing margin. Crossveins present between them. CuA branches continuously forked before termination. The space between CuA and CuP dilated before CuA forked. CuP parallel with posterior margin, with space between them broad. CuP pectinately branched Fig. 12. Photograph and line drawing of Sialium sinicus sp. nov. Holotype CNU-NEU-NN

17 C. Shi et al. / Cladistics 31 (2015) (c) (d) Fig. 13. Wing venation of Sialium sinicus sp. nov. Holotype CNU-NEU-NN Left forewing; right forewing; (c) left hind wing; (d) right hind wing.

18 472 C. Shi et al. / Cladistics 31 (2015) with numerous branches continuously forked. 1A elongated and forked. 2A forked. 3A short. Hind wing costal crossveins forked more than in forewing. Rs separated from R1 before basal one-tenth of wing length. MA separated from Rs stem before basal one-quarter of wing length. MP forked before the origin of Rs. MP1 straight, shallowly forked near termination. MP2 long, pectinately branched, with 11 closely spaced branches forked before termination. CuA parallel to posterior margin with a broad space between the two. CuA pectinately branched with eight branches continuously forked before terminating on posterior margin. One series of crossveins discontinuously interlinking CuA branches. CuP long, pectinately branched with six branches, without crossveins between them. 1A and 2A short and forked. Type material. Holotype CNU-NEU-NN Locality and horizon. Liutiaogou Village, Ningcheng County, Chifeng City, Inner Mongolia Autonomous Region, China. Yixian Formation, Early Cretaceous. Sialium minor sp. nov. Figs Etymology. From Latin parvus, -a, -um (comparative minor), small (smaller). Diagnosis. Wing markings present midway between Sc and R1, MP1 and MP2, along outer gradate crossvein series area on forewing, and the area surrounding the fusion of Sc and R1 on both forewing and hind wing. Fig. 14. Photograph and line drawing of Sialium minor sp. nov. Holotype CNU-NEU-LB

19 C. Shi et al. / Cladistics 31 (2015) (c) Fig. 15. Wing venation of Sialium minor sp. nov. Holotype CNU-NEU-LB Left forewing; left hind wing; (c) right hind wing. Description. Holotype CNU-NEU-LB Forewing preserved length 14.3 mm, preserved width 4.1 mm. Hind wing preserved length 13.6 mm, preserved width 3.8 mm. Wings elongated. Forewing bearing small markings in the basal posterior part, midway between Sc and R1, MP1 and MP2, along outer gradate crossvein series area on forewing, and the area surrounding the fusion of Sc and R1. Hind wing bearing small markings dispersed in the distal part. Forewing costal crossveins seldom forked before pterostigma area, and progressively more numerous from pterostigma to the termination of Sc + R1. Rs separated from R1 near wing base. MA separated from Rs stem near basal one-third of wing length. MA dichotomously forked proximally, almost at the same level as the origin of the first Rs branch. The first Rs branch separated from Rs stem distally, almost midway along wing length. Rs with 12 branches. MP forked between the origin of Rs and the separation of MA. One oblique vein present between Rs stem and M stem. MP1 forked closely before termination. MP2 pectinately branched with at least seven branches. CuA long, with few branches. CuP pectinately branched with numerous branches. 1A long and forked. Hind wing venation similar to that on forewing, but MP forked before the origin of Rs. MP2 pectinately

20 474 C. Shi et al. / Cladistics 31 (2015) Fig. 16. Photograph and line drawing of Sialium minor sp. nov. Paratype CNU-NEU-LB branched with branches, forming a triangular area midway along wing. CuA pectinately branched with fewer branches than MP2. CuA branches terminating on posterior margin. CuP pectinately branched with few branches. Locality and horizon. Huangbanjigou Village, Chaomidian County, Beipiao City, Liaoning Province, China. Yixian Formation, Early Cretaceous. Paratype CNU-NEU-LB Forewing preserved length 15.6 mm, preserved width 4.1 mm. Hind wing preserved length 13.1 mm, preserved width 4.1 mm. Wings elongated. Wing markings present midway between Sc and R1, MP1 and MP2, along outer gradate crossvein series area on forewing, and the area surrounding the fusion of Sc and R1 on both forewing and hind wing. Forewing costal crossveins seldom forked, but progressively denser with more forks from pterostigma area. Sc and R1 approximating basally, fused distally. MA separated from Rs stem near basal one-third of wing length. The first Rs branch separated from the Rs stem distally, almost midway along wing length. MP forked before the basal one-fifth of wing length. One oblique vein present between Rs stem and M stem right after the fork of MP. MP1 forked near termination. MP2 pectinately branched with nine branches terminating on outer margin. Hind wing costal crossveins not forked except from pterostigma to termination of Sc + R1. MA separated from Rs remote from wing base. MP1 forked near termination. MP2 pectinately branched with about eight branches. CuA long, pectinately branched. Locality and horizon. Huangbanjigou Village, Chaomidian County, Beipiao City, Liaoning Province, China. Yixian Formation, Early Cretaceous. Nymphites sp. B Figs 18 and 19 Diagnosis. Legs (at least hind) with tibial spurs; forewing costal crossveins seldom forked; hind wing MP2 with four branches, CuA with at least five branches. Description. Forewing preserved length 23.7 mm, preserved width 9 mm. Hind wing preserved length 33.1 mm, preserved width 9.5 mm. Compound eye medium-sized; antenna filiform; prothorax as wide as head; pterothorax dilated; legs slender; tibiae with a pair of apical spurs. Forewing costal crossveins seldom forked before pterostigma area. CuA pectinately branched. Hind wing outer margin waved. Costal crossveins only forked from pterostigma area. Sc and R1 closely parallel. MA separated from the basal part of Rs stem, but remote from wing base. Rs with seven branches. MP1 forked closely before termination. MP2 pectinately branched with four branches. CuA pectinately branched with at least five branches.

21 C. Shi et al. / Cladistics 31 (2015) (c) (d) Fig. 17. Wing venation of Sialium minor sp. nov. Paratype CNU-NEU-LB Left forewing; right forewing; (c) left hind wing; (d) right hind wing.

22 476 C. Shi et al. / Cladistics 31 (2015) Fig. 18. Photograph and line drawing of Nymphites sp. B. specimen CNU-NEU-NN Material. CNU-NEU-NN Locality and horizon. Liutiaogou Village, Ningcheng County, Chifeng City, Inner Mongolia Autonomous Region, China. Yixian Formation, Early Cretaceous. Comments. This specimen is tentatively assigned to the genus Nymphites based on the four branches of hind wing MP2 (referred to as MP by Shi et al., 2013) and the presence of tibial spurs. Due to the incomplete preservation of the specimen, there are not enough significant observable characters to assign it to any published species, or to formally name it as representing a new species. Species of Nymphites have been described from the Middle Jurassic of China and the Late Jurassic of Germany. This specimen could be the only representative of Nymphites from the Early Cretaceous, which indicates the genus might have survived for over 40 Myr in the Late Mesozoic. Nymphites is the earliest representative in Nymphinae, bearing a narrow costal area and tibial spurs. Besides the unnamed Nymphites species described here, tibial spurs were also found on the Middle Jurassic species Nymphites bimaculatus Shi, Makarkin et Ren, 2013, and an unnamed species Nymphites sp. A (Shi et al., 2013). Discussion Phylogenetic position of Nymphidae Myrmeleontiformia is a well-established and accepted clade within Neuroptera and is almost universally considered to comprise the extant families Psychopsidae, Nymphidae, Myrmeleontidae, Ascalaphidae and Nemopteridae (e.g. MacLeod, 1964; Grimaldi and Engel, 2005; Winterton et al., 2010; Asp ock et al., 2012), along with at least the extinct families Palaeoleontidae, Araripeneuridae and Babinskaiidae (Yang et al., 2012; Makarkin et al., 2013b). The phylogenetic relationships among the various neuropteran families are not universally accepted within Myrmeleontiformia (Asp ock et al., 2001, 2012; Asp ock, 2002; Winterton et al., 2010), with varying hypotheses of relationships among the families, differing mainly in the relative positions of Nemopteridae and Psychopsidae. Based solely on morphological characters of the wing venation, genitalia and larval mandible, some authors place Nymphidae as the sister group of Myrmeleontidae + Ascalaphidae (Handlirsch, ; Withycombe, 1925; Asp ock et al., 2001, 2012; Asp ock, 2002; Beutel et al., 2010a, b). Yet the phylogenetic analysis by Winterton et al. (2010) recovered Nymphidae as the sister group of Myrmeleontidae, Ascalaphidae and Nemopteridae, and appears to be the bestsupported hypothesis for placement for the family, based on both DNA sequence data and morphology of extant and extinct forms (e.g. New, 1984; Oswald, 1998; Makarkin et al., 2013b). Phylogenetic relationships within Nymphidae Nymphidae have been treated by some early authors as two separated families, Myiodactylidae (= Myiodactylinae herein) and Nymphidae sensu stricto (s.s.) (= Nymphinae herein), with the former sometimes placed near Osmylidae (Handlirsch, ; Withycombe, 1925; Tillyard, 1926; cf. Esben-Petersen, 1914;