Discovery of the pincer wasp Thaumatodryininae (Hymenoptera, Dryinidae) in Burmese amber, with description of a new genus and the first phylogenetic analysis of the subfamily

Thaumatodryininae is a small subfamily of Dryinidae, known to attack nymphs of auchenorrhynchous Flatidae (Hemiptera). Only one genus is recognized, Thaumatodryinus Perkins, with 35 species including fossil and extant taxa. Currently, the oldest record for the genus is from Baltic amber. Here, we present the first record of Thaumatodryininae from mid-Cretaceous Burmese amber with the description of † Thaumatorrhinos athrix gen. et sp. nov. , derived from the first phylogeny for this subfamily based on morphological characters. The placement of † Thaumatorrhinos gen. nov. in Thaumatodryininae and the phylogenetic relationships of this subfamily within Dryinidae are discussed.


Introduction
Knowledge about the fossil fauna of insects preserved in amber has increased considerably in recent years, especially those from mid-Cretaceous Burmese amber, from Kachin, Myanmar (Ross 2021).This amber deposit, with an estimated age between 99-98 Mya (Shi et al. 2012), has revealed a number of unique insect groups and many of those, belonging to Hymenoptera, turned out to be key elements for our understanding of the phylogenetic relationships among the main lineages of Chrysidoidea (e.g.Lucena and Melo 2018;Zhang et al. 2018;Martynova et al. 2019;Melo and Lucena 2020;Olmi et al. 2020).
Although there are many taxonomic studies dealing with the family Dryinidae, only a few phylogenetic studies have been published, as by Carpenter (1999), Tribull (2015), and Branstetter et al. (2017).These studies used different groups and approaches, whether morphological, molecular or phylogenomic, and in all of them Dryinidae were recovered as a monophyletic group.Up to now, Tribull's (2015) study was the most representative investigation of the relationships within Dryinidae and her hypotheses provided support for recognizing Thaumatodryininae as a subfamily distinct from Dryininae.
Thaumatodryininae are one of the smallest subfamilies of Dryinidae, with 35 described species placed in the single genus Thaumatodryinus Perkins (Martins and Melo 2020;Brazidec and Perrichot 2023).It has an almost worldwide distribution, being absent only from the Palearctic region, and is known to attack nymphs of the auchenorrhynchous Hemiptera of the family Flatidae (Guglielmino et al. 2013;Martins and Melo 2020).One of the diagnostic characters of Thaumatodryinus is the presence of rhinaria on flagellomeres 3-8 accompanied by long and delicate setae, whose length is longer than the diameter of the flagellomere (Martins and Melo 2020).These sensory structures are present only on the antennae of females belonging to Apodryininae, Dryininae, Gonatopodinae, and Thaumatodryininae, and seem to be involved in host location (Olmi 1984;Riolo et al. 2016).
Additional characters for the recognition of this genus are the bulging hemispherical compound eyes, the vertex with a convex contour in frontal view, and the elongated claw of the pincer with a simple apex, lacking subapical teeth.
We provide herein the first record of Thaumatodryininae in mid-Cretaceous Burmese amber, represented by a new genus and species.The placement of the new taxon is corroborated by the first phylogenetic investigation, based on morphological data under an exemplar approach, involving a broad sample of dryinid representatives and providing a series of newly proposed characters.

2.
Material and methods

Taxonomic study
The studied amber piece came from the Hukawng Valley, near Tanai, Kachin state, in northern Myanmar, whose age has been estimated to be around 99-98 Mya (Shi et al. 2012).The piece is deposited in the Departament of Zoology, Universidade Federal do Paraná, Curitiba, Brazil (DZUP).In order to have a better view of the inclusion, the piece was manually trimmed with a jewellery saw and ground with wet emery paper (grit sizes of 800 to 3000).Final polishing was obtained using a sanding sponge pad (grit size of 5000), followed by rubbing in a soft cloth.Morphological terminology follows Olmi and Virla (2014); specific terms used for integumental sculpture, follow Olmi and Virla (2014) and Harris (1979); we adopted Brothers's (2011) terminology for the fore wing venation, with some modifications (Fig. 1).The term "rhinaria" (sensu Olmi 1984) is interpreted herein as equivalent to "ADOs" = Antennal Dorsal Organs (sensu Riolo et al. 2016).The classification adopted for the species groups in Dryinus follows Martins (2018).
In the description of the genus and species and in the character descriptions the following abbreviations are used: OL -refers to the minimum distance between the inner edges of the lateral ocellus and the median ocellus; OOL -refers to the minimum distance from the outer edge of the lateral ocellus to the eye inner margin; OPLrefers to the minimum distance from the posterior edge of a lateral ocellus to the occipital carina; POL -refers to the minimum distance between the inner edges of the lateral ocelli; and TL -refers to the minimum distance from the posterior edge of the eye to the occipital carina.The measurements provided for ocellar ratio, antennomeres, and the fore-leg articles represent relative values.
The inclusions were studied using a Leica M125 stereomicroscope.Color images of †Thaumatorrhinos athrix gen.et sp.nov.were obtained by a LEICA DFC295 digital camera.Image stacking was done using the software Zerene Stacker 1.04 Built T2021-08-28-1410.The figure plates were prepared using Adobe Photoshop (version CS6).

Phylogenetic analysis
The cladistic analyses were based on a matrix of 100 characters and 22 terminal taxa (Table 1 and Table S1), including extant and fossil species from Dominican and Burmese amber.Most characters were taken from the female morphology, as the taxonomy of the family is mostly based on this sex.For those characters involving the male morphology, we coded them based on genus-level groundplans; for taxa in which the males are unknown, the terminal was left with missing data.The characters, all from the external morphology of the adult wasps, were numbered according to their respective tagma, from anterior to posterior (head, mesosoma, and metasoma).We used a question mark (?) for missing information, and a hyphen (-) was assigned to inapplicable states.Outgroups were chosen from different genera belonging to more basal subfamilies of Dryinidae for which we had available material (Anteoninae, Aphelopinae, Bocchinae, and Conganteoninae).Representatives of the more derived subfamilies, Gonatopodinae and Dryininae, were included in the ingroup in order to test the position of the new genus and the monophyly of Thaumatodryininae (Table 1).
The characters and their states were assembled in a matrix, subsequently converted to a text file, and then formatted as a Nona file.Multistate characters were treated as non-additive (Fitch 1971).The heuristic searches for the most parsimonious trees were conducted in TNT v.1.6(Goloboff and Morales 2023), using the following specifications in the analyses: space for 99999 trees in memory; traditional tree search; random seed 0; 1000 replications; TBR algorithm; 10 trees saved per replication.Analyses were carried out under implied weights (with the default k = 3) as implemented in TNT.Parsimony analyses under implied weights are advocated to improve phylogenetic resolution for resolving conflict between characters in favor of those exhibiting a lower degree of homoplasy (Goloboff 1993;Goloboff et al. 2008;Goloboff 2014).Support for the branches was estimated through symmetric re-sampling (Goloboff et al. 2003), also in TNT v.1.6(traditional tree search -TBR = 1000 replications; 10000 re-sampling replications).Both the optimization of the characters and the visualization of the cladograms were done in the software Winclada 1.00.08 (Nixon 2002), with only unambiguous changes shown.In the topologies analyses, the value of symmetric resampling was considered above 15%.For comparative purposes, an equal-weight analysis (Fig. S1) was also carried out in TNT.Trees were rooted between Anteoninae and the clade containing Conganteoninae + Bocchinae + Aphelopinae, based on an unpublished reanalysis of Tribull's (2015) dataset.

Results
In this study we present the first phylogenetic analysis for Dryinidae, based on morphological data under an exemplar approach, combining fossil and extant taxa and using a set of newly proposed characters from all body regions.The cladistic analysis was based on a matrix of 100 characters and 22 terminal taxa (Table 1 and Table S1): 36 from the head; 60 from the mesosoma, and four from the metasoma.Most of the characters apply to females; when specific to males, these are indicated as such.We assembled a dataset with 100 characters, of which only 14 (indicated in the respective character comment) had been used previously (Carpenter 1999), showing how incipient is our current knowledge of the relationships within Dryinidae based on morphology.Among these characters, 81 were coded as binary and 19 as multistate.For each character, the number of steps (L), consistency index (ci), and retention index (ri), as found in the weighted analysis, are provided.Those indicated as non-informative by the analyses do not have ci and ri values.
3. Mandible, number of teeth (male): (0) four; (1) three.(L: 1; ci: 100; ri: 100).-State (1) applies to the genus Dryinus Latreille (Dryininae) as well as to the genera of Gonatopodinae (Gonatopus Ljungh, Neodryinus Perkins and Pareucamptonyx Olmi).Species of Dryinus and Gonatopus exhibit strong sexual dimorphism.We examined a significant number of male specimens and found that the number of teeth in the mandible is constant.In this study, it is assumed that all genera of these two subfamilies have the same number of teeth.This character corresponds partially with character 14 of Carpenter (1999).9. Clypeus, apical margin shape: (0) without recess;

Mandible
(1) with a medial recess.(L: 1; ci: 100; ri: 100).-State (1) applies to the species of Dryinus belonging to the magnificus and ruficeps groups.This character corresponds partially with character 10 of Carpenter (1999).49.Ventral surface of prepectus: (0) independent lateral sclerites, separated from one another ventrally by remainder of the mesopleura; (1) lateral sclerites extending ventrally and fused medially.(L: 1; ci: 100; ri: 100).-State (0) of this character applies to Aphelopinae, Bocchinae and Conganteoninae (although the pronotum is fused to the prepectus in these subfamilies, we consider that these groups have this condition), Anteoninae and Thaumatodryininae.State (1) applies to Dryininae and Gonatopodinae, in which the prepectus is fused ventrally and their halves are not separated by the remainder of the mesopleura. is attributed when the notauli occupy the entire length of the mesoscutum, that is, when they are considered complete.

Ratio of the smallest distances between the notauli in the anterior and posterior portions of the mesoscutum (female):
(0) less than three; (1) equal to or greater than three.(L: 2; ci: 50; ri: 0).-State (1) of this character is considered when the notauli almost completely converge in the posterior portion of the mesoscutum and, it applies to †Thaumatorrhinos gen.nov.(Thaumatodryininae) and †Harpactosphecion (Dryini nae).61.Propodeum, shape: (0) dorsal surface of the propodeum separated from the posterior surface by a wellmarked edge, the two surfaces practically forming a right angle; (1) dorsal surface of the propodeum continuous with the posterior surface, giving the propodeum a smoothly convex profile in lateral view.(L: 3; ci: 33; ri: 77).64.Protrochanter, its length in relation to its maximum width: (0) up to 2.9 × its width; (1) greater than 3 × its width.(L: 1; ci: 100; ri: 100).-State (0) applies to the species of Anteoninae, Aphelopinae, Bocchinae, and Conganteoninae.State (1) applies to Thaumatodryininae, Gonatopodinae, and Dryininae (although the species of Dryinus of the bocainanus group have a ratio less than 3, the terminal representing this group was here attributed this state).This character corresponds partially with character 24 of Carpenter (1999).71.Articulation of 4 th protarsomere on 3 rd : (0) tightly articulated, tarsomeres juxtaposed and with the same diameter; (1) 3 rd tarsomere with a smaller diameter than 4 th , the latter apparently partially loose and hanging from the former.(L: 2; ci: 50; ri: 50).(L: 1; ci: 100; ri: 100).-These "hooks" are projections of the tarsomere integument, forming a blade with a set of bristles at its apex.

Setae on the inner margin of the
79. Shape of the setae on the enlarged claw: (0) short, thin, and with a tapered apex, differing from the lamellae of the 5 th protarsomere; (1) longer and thicker, commonly with an enlarged apex, and similar to the lamellae of the 5 th protarsomere.(L: 2; ci: 50; ri: 66).-This character applies only to terminals coded as ( 0) and ( 1) in the preceding character.State (0) applies to specimens of Gonatopodinae and species of Dryinus (Dryininae) of the bocainanus group.State (1) applies to Thaumatodryininae, Gonatopodinae, and to the remaining Dryininae.1) is a synapomorphy of Gonatopodinae.This character corresponds partially with character 30 of Carpenter (1999).93.Pterostigma, shape of inner margin: (0) semicircular; (1) elongated (Fig. 1).(L: 2; ci: 50; ri: 66).-The pterostigma is considered semi-circular when its inner margin is a segment of a circle.

Metasoma
96. Flap of tendon on tergum I: (0) small and narrow, its width distinctly less than 0.5 × the width of the propodeal orifice; (1) well-developed, distinctly wide (at least as wide as 0.5 × the width of the propodeal orifice).(L: 1; ci: 100; ri: 100).-The flap on tergum I is well developed in Thaumatodryininae, Gonatopodinae and Dryininae.There is some variation in shape, especially in Gonatopodinae.

Phylogenetic relationships
The phylogenetic analysis under implied weighting resulted in one most parsimonious tree shown in Fig. 2  group and sister group of a clade composed of the subfamilies Gonatopodinae and Dryininae, with strong support of symmetric resampling (100%).This major clade was supported by seven unique transformations, which can be interpreted as synapomorphies: flagellomeres with rhinaria (20:1); compound eye with frontal facets of the lower third about 2 × as large as the dorsal and latero-posterior ones (26:1); protrochanter longer than 3 × its width (64:1); apex of the enlarged claw with one subapical tooth (82:1); tarsal claws of the middle and posterior legs forming a smooth, open curve (84:1) metacoxal base with a well-developed lamella or a lamelliform lobe (88:1); flap of tendon on tergum I well-developed, distinctly wide (at least as wide as 0.5 × the width of the propodeal orifice) (96:1); and three homoplastic transformations: anterior condyle of the mandible, in relation to the antennal alveolus, aligned with the outer margin of the alveolus (narrow clypeus) (8:1); lack of groove along outer orbit (24:1); fore wing with 3Rs&4Rs longer than 2r-rs (95:1) (Figs 1, 3E).
Our phylogenetic results placed the Burmese taxon, described here as a new genus and species, †Thaumatorrhinos athrix gen.et sp.nov.(see below), as sister group to Thaumatodryinus (represented here by three species, the fossil †T.fuscescens from Dominican amber; T. koebelei, the type species of the genus, from Australia; and T. macilentus from the Neotropical region).The Thaumatodryininae clade (Fig. 2) has a support of 98% in the symmetric resampling and three unique transformations optimized in this branch: mandible (Fig. 3D) with an abrupt curve near base, making almost a right angle (6:1); vertex (Figs 3A, C, 4A, 5B) with a distinctly convex profile (28:2); and 3 rd protarsomere (Fig. 4B) without differentiated bristles longer than tarsomere (70:1).Four homoplastic transformations also provide support for the clade: antennal alveolus (Fig. 5A) separated from the epistomal suture by at least half of alveolus diameter (7:1); pronotum with transverse impression located at its mid length (40:1); apex of the enlarged claw with a lamella about 1.5 × the length of the others (80:2); and tooth at the apex of the elongated claw without a curvature and its dorsal surface flattened (83:1).The phylogenetic hypothesis recovered here, with Thaumatodryininae apart from Dryininae, agrees with the phylogenetic results obtained by Tribull (2015) from molecular data.
Thaumatodryinus, represented here by three species, was supported by 98% in the symmetric resampling and by one unique transformations: rhinaria with long and delicate setae exceeding the diameter of the flagellum Additional results recovered here involve the monophyly of the group containing Dryininae and Gonatopodinae, supported by 100% in the symmetric resampling.Gonatopodinae was represented here by three genera (Neodryinus Perkins considered the sister-group of Gonatopus Ljungh plus Pareucamptonyx Olmi) and Dryininae by three genera (Dryinus Latreille, Gonadryinus Olmi and †Harpactosphecion Haupt).Also, the results confirm the synonymy indicated in Martins (2018) of Megadryinus Richards under Dryinus, represented here by D. magnificus (Richards).Diagnosis.Head with convex vertex; occipital carina complete; frontal line absent; rhinaria present on all antennal flagellomeres and occupying most of flagellomere length; clypeus with mid portion of anterior margin straight; mandible with four teeth, second one shorter than the others (rudimentary); pronotum crossed by strong transverse impression; notauli complete and converging posteriorly; fore wing stigmal vein with 3Rs&4Rs longer than 2r-rs; propodeum with dorsal surface shorter than posterior surface, the latter with two longitudinal carinae.4A) with long base and apex with four teeth, the second subapical tooth (Fig. 5A) rudimentary; maxillary and labial palpi with, respectively, 5 and 3 palpomeres.-Pronotum: saddle-shaped and crossed by strong transverse impression at central portion; notauli complete and strongly converging posteriorly.-Fore wing: (Fig. 3A-D) hyaline and stigmal vein with 3Rs&4Rs longer than 2r-rs (Fig. 3E), almost reaching the wing apical margin; veins Rs+M, 2Cua and 3Cu present; divergence between M and Cu veins coinciding with cu-a (Fig. 3E).-Protarso mere: Apex of 3 rd protarsomere (Fig. 4B) with 4 long setae; chela (Fig. 4B) with rudimentary claw; enlarged claw with one row of lamellae and apex reaching inner margin of 5 th protarsomere; apex of enlarged claw pointed and without lateral teeth; tibial spur formula 1/1/2.Propodeum with two longitudinal carinae on posterior surface.

Order
Etymology.The genus is named after its peculiar rhinaria, from the Greek thaumatos (wonder, marvel) and rhinos (of the nose or snout).The name is feminine.
Remarks.†Thaumatorrhinos gen.nov. is closely related to Thaumatodryinus and its placement in Thaumatodryin- inae is supported by the head with convex vertex leaving the compound eyes located on the sides of the head; antenna with filiform flagellomeres; base of the mandible with a flat area; pronotum with transverse impression located at its mid length; and apex of 3 rd protarsomere (Fig. 4B) with four long setae.However, it differs from Thaumatodryinus by the mandible with three large teeth and one shorter rudimentary tooth (Fig. 5A); antenna with rhinaria on all flagellomeres and occupying about their entire extension (Fig. 5B); occipital carina complete (Fig. 5B); notauli percurrent and indicated as deep sulci; apex of enlarged claw forming a gentle curvature in relation to the main shaft, lateral teeth absent; dorsal surface of propodeum separated from its posterior surface by a well-marked edge, the two surfaces practically forming a right angle; and posterior surface of propodeum with a pair of longitudinal carinae.†Thaumatorrhinos athrix sp.nov.Etymology.We named the species after its bare rhinaria, from the Greek athrix (without hair).
Diagnosis.Same as for the genus.
Remarks.Same as for the genus.

Discussion
Thaumatodryininae were recovered as a monophyletic group and placed distantly from Dryininae, a result that corroborates the hypothesis presented by Tribull (2015) using molecular data.The placement of Thaumatodryin- inae as a clade apart from Dryininae was strongly supported by the data.Our analyses also allowed the positioning of a mid-Cretaceous amber fossil, described here as †Thaumatorrhinos gen.nov., in Thaumatodryininae and coming out as sister group of Thaumatodryinus, previously the only genus recognized in this subfamily.Therefore, we expand the scope of the subfamily by adding a new lineage, which exhibits a series of plesiomorphic features when compared to Thaumatodryinus.The discovery of †Thaumatorrhinos gen.nov.revealed that Thaumatodryininae can be considered an independent lineage at least since the mid-Cretaceous, thus being much older than the previously assumed Eocene age (Martins and Melo 2020).This new fossil also allowed us to refine the scenario involving the evolution of the rhinaria, a remarkable feature present on the female antennae of some dryinid subfamilies (Olmi 1984).The term rhinaria was introduced by Olmi (1984: 19-20) to refer to the fine grooves on the flagellomeres.They represent specialized sensory organs, apparently involved in host finding, and their ultrastructure has been investigated by Riolo et al. (2016), who renamed them as "antennal dorsal organs".The condition of the rhinaria in †Thaumatorrhinos gen.nov.resembles that observed in Gonatopodinae and Dryininae, except for being present also on the two basal-most flagellomeres and for extending along the entire length of the flagellomeres.Since the rhinaria in †Thaumatorrhinos gen.nov.(and for that matter in Gonatopodinae and Dryininae as well) lack the characteristic long setae seen in Thaumatodryinus, we can conclude that the latter genus has an apomorphic condition.
Placement of †Thaumatorrhinos gen.nov. in Thaumatodryininae is strongly supported by the following characters: mandible with abrupt curvature near the base, making almost a right angle; vertex with a distinctly convex profile; 3 rd protarsomere with differentiated bristles longer than the tarsomere; antennal alveolus separated from the epistomal suture by at least half of the alveolus diameter; pronotum with transversal impression located at its mid length.Despite that, †Thaumatorrhinos gen.nov.exhibits many features that clearly separates it from Thaumatodryinus, justifying its recognition as a distinct genus.
Possession by †Thaumatorrhinos gen.nov. of a small, "rudimentary" tooth in the mandible is also observed in the subfamilies Aphelopinae, Bocchinae, and Conganteoninae.Character optimization indicated independent gains of this condition in the two lineages (see Fig. 2, character 5:0).Although being a slightly less parsimonious explanation, the condition in †Thaumatorrhinos gen.nov.could also represent a retained plesiomorphy, with the more derived condition seen in Thaumatodryinus, with four progressively enlarged teeth, having evolved independently from that seen in Gonatopodinae and Dryininae.
Currently, several fossil species belonging to different groups of Dryinidae have been described from different fossil deposits, mainly from Burmese amber (Martynova et al. 2019(Martynova et al. , 2020;;Martins andMelo 2019, 2020;Perkovsky et al. 2019;Tribull et al. 2020;Olmi et al. 2020Olmi et al. , 2021Olmi et al. , 2022;;Wang et al. 2021), especially taxa belonging to Dryininae.Although they have not been included in our phylogenetic analyses, a series of unequivocal characters support the position of †Thaumatorrhinos gen.nov. in Thaumatodryininae, and not in Dryininae, such as: mandible with abrupt curvature near the base, making almost a right angle; vertex with a distinctly convex profile; 3 rd protarsomere without differentiated bristles longer than the tarsomere; antennal alveolus separated from the epistomal suture by at least half of the alveolus diameter; pronotum with transversal impression located at its mid length; apex of the enlarged claw with a lamella about 1.5x the length of the others; and tooth at the apex of the elongated claw not curved with a flattened dorsal surface.Additional characters differentiating †Thaumatorrhinos gen.nov.from other extinct genera of Dryininae, such as †Hybristodryinus Engel, are the presence of rhinaria in all flagellomeres; fore wing with vein 3Rs&4Rs much longer than 2r-rs and reaching apex of wing; and the tibial spur formula 1:1:2.
Our results reinforce the importance of fossils for improving our understanding of the evolutionary history of different insect groups, in particular of Dryinidae.These records, together with the study of the extant fauna and using phylogenetic tools, have made it possible to correctly position, interpret and reinterpret different characteristics present in these lineages and to understand the evolutionary history of the family.

Figure 2 .
Figure 2. Most parsimonious tree resulting from a cladistic analysis under implied weighting (k = 3) of 100 morphological characters and 22 terminal taxa, focusing in Thaumatodryininae (Hymenoptera, Dryinidae).Character-state transformations are shown under unambiguous optimization, depicted as solid (unique transformations) and empty circles (reversals or multiple transformations).Branch support indicated for the major clades is derived from symmetrical resampling.
2r-rs, length: (0) shorter or equal; (1) longer (Figs 1, first metasomal segment: (0) basal portion of sternum I (petiole) in the same plane as the rest of the sclerite; (1) basal portion of the sternum I forming a strong angle in relation to the surface of the rest of the sclerite.(L: 1; ci: 100; ri: 100).

Figure 4 .
Figure 4. †Thaumatorrhinos athrix gen.et sp.nov.A Head, frontal view; B protarsomeres and chela; C head and part of mesosoma, dorsal view and details of flagellomeres with rhinaria.D flagellomeres 7-8 with details of rhinaria.Scale bar: 0.2 mm; B-D at the same scale.

Table 1 .
List of terminal taxa of Dryinidae (Hymenoptera, Chrysidoidea) used in the phylogenetic analysis.Country of origin (or fossil deposit) and acronyms of the depository institutions are indicated.

27. Upper frons, relation to eye surface
Thaumatodryinus, in which each flagellomere has four long setae, one pair at each end of each rhinarium.This seems to result from a bulging of the compound eyes in these lineages, in which the eyes are projected from the head laterally and their surface does not form a continuous plane with the frons surface.
). -State (0) applies only to †Thaumatorrhinos gen.nov.State (1) applies to Thaumatodryinus and state (2) applies to Gonatopodinae and Dryininae.23.Rhinaria, setation: (0) with long bristles exceeding the diameter of the flagellomere; (1) bristles absent or rhinaria accompanied by short setae less than the diameter of the flagellomere.(L:1; ci: 100; ri: 100).-State(0) applies to 26.Compound eye, location on head: (0) occupying the anterior portion of the dorsal region of the head; (1) occupying the lateral region of the head (Figs 4A, 5A);(2) occupying the entire dorsal region of the head and parallel to the vertex.(L: 2; ci: 100; ri: 100).-State (0) applies to Anteoninae, Aphelopinae, Bocchinae and Conganteoninae, in which the genal bridge is reduced and the vertex has a larger extension, causing the eye to be restricted to the anterior portion.State (1) applies to Thaumatodryininae, in which the genal bridge and the vertex have approximately the same length, causing the eyes to be displaced laterally, while state (2) applies to Gonatopodinae and Dryininae, in which the genal bridge is elongated and almost parallel to the vertex, causing a displacement of the buccal apparatus to the anterior region, characterizing a prognathous condition, while the eyes occupy almost the entire surface.: (0) in the same plane or at a slightly lower level; (1) at a distinctly lower level.(L: 1).-An upper frons at a distinctly lower level compared to the eye surface is found in Gonatopodinae and Dryininae.species in the ruficeps group of Dryinus is in a distinct lower plane compared to the eyes and has a strongly concave profile.29.Mid ocellus, position in relation to lateral ocelli: (0) placed not far apart, OL 0.5-1.5 × POL; (1) placed far apart, OL at least 2 × POL.(L: 1).-State (1) is closely associated with the excavated vertex in Dryinus.