A mantidfly in Cretaceous Spanish amber provides insights into the evolution of integumentary specialisations on the raptorial foreleg

Multiple predatory insect lineages have developed a raptorial lifestyle by which they strike and hold prey using modified forelegs armed with spine-like structures and other integumentary specialisations. However, how structures enabling the raptorial function evolved in insects remains largely hypothetical or inferred through phylogeny due to the rarity of meaningful fossils. This is particularly true for mantidflies (Neuroptera: Mantispidae), which have a scarce fossil record mostly based on rock compressions, namely isolated wings. Here, Aragomantispa lacerata gen. et sp. nov. is described from ca. 105-million-year-old San Just amber (Spain), representing the oldest and one of the few mantidflies hitherto described from amber. The fossil shows exquisitely preserved forefemoral spine-like structures composed of integumentary processes each bearing a modified seta, and prostrate setae on foretibiae and foretarsi. The fine morphology of these structures was unknown in fossil mantidflies. An assessment of integumentary specialisations from raptorial forelegs across mantispoid lacewings is provided. The present finding reveals how the specialised foreleg armature associated to the raptorial lifestyle in extant mantidflies was present yet not fully established by the Early Cretaceous, at least in some lineages, and provides palaeontological evidence supporting certain evolutionary patterns of acquisition of integumentary specialisations related to the raptorial function in the group.

Diagnosis. Scape moderately elongate, about 4× longer than wide basally. Forecoxa not particularly elongate, shorter than forefemur (ratio forecoxae/forefemoral length 0.6). Forefemur not laterally flattened ventrally, widening distally and reaching its maximum width slightly beyond its midlength. Forefemur slightly longer than combined length of foretibia and foretarsus (about 1.1×). Forefemur with three types of spine-like structures composed of integumentary processes (IPs) each bearing a modified seta distally, arranged in two longitudinal rows: (1) two ectal and two ental major IPs bearing modified setae; ratio IP length/modified seta length of largest IP (basalmost, ental) 7:1, same ratio of three remaining IPs 3:1; (2) about ten ectal and five ental minor IPs bearing needle-like setae placed on proximal three quarters, ratio IP length/needle-like seta length about 1:3; (3) three ectal and three ental thick, minor IPs bearing thick setae on distal quarter, ratio IP length/thick seta length 3:2. Foretibia slightly arched ventrad, ventrally bearing a single row of closely-spaced prostrate setae, visible only on the distal half of the tibia. Foretarsus pentamerous, with tarsomeres cylindrical and compact. Foretarsomere 1 not particularly elongate, not produced apically. Foretarsomere 5 the longest. Foretarsomeres 1-4 ventrally with one or two transverse pairs of prostrate setae each. Foretarsal prostrate setae distinct from those on foretibiae, i.e., thicker, with basal stretch erect at about 45° angle and a distal stretch abruptly inclined forwards and running parallel to the tarsus (not directed towards the cuticle). Claws paired and simple (not bifid or multipronged) in all legs. Arolium present in all legs. Meso-and metathoracic legs with tarsomeres 3 and 4 subequal in length. Hind wing with single trichosors along all anterior margin, with costal space very narrow; Sc meeting RA at about 2/3 of the wing length, pterostigmal area hyaline; two ra-rp crossveins before the pterostigmal area, 1rp-ma crossvein straight (not sigmoidal).  www.nature.com/scientificreports www.nature.com/scientificreports/ articulations), and the forelegs (excluding the right foreleg beyond the mid femur) are preserved in good condition. A basal third portion of a forewing, most part of a hind wing, and three distal fragments of mid-/hind legs are also preserved. Syninclusions: a partial snakefly (Raphidioptera) wing (asterisk in Fig. 1a) and possibly fragments of its legs (one of them showing distinct maculations); a small hymenopteran, and a few other indeterminate insect fragments (legs, eyes, microlepidopteran scales, etc).
Diagnosis. As for the genus (see above).
Description. Sex unknown. Body medium-sized, inferred length 8-9 mm from mandibles to end of the abdomen (Fig. 1a).
Forewing with only a fragment from its basal third preserved, 1.60 mm wide, with weakly marked trichosors likely present anteriorly (Figs 2d and 3e). Costal space with two preserved crossveins, the basalmost narrowly forked. Crossvein 1cua-cup preserved, situated beyond branching of RP. Posterior CuP branches shallowly twigged at wing margin. Vein 1A with one simple branching, its anterior branch shallowly twigged.
Hind wing 5.21 mm long, about 1.55 mm wide, with single trichosors between veins along its preserved margin (Figs 2e and 3f). Apex rounded. Costal space very narrow, with a few costal veinlets preserved proximally and around the pterostigmal area, all simple (not twigged). Costal veinlets not apparent. Pterostigmal area hyaline. Sc meeting RA at about 2/3 of the wing length. Two ra-rp crossveins before Sc reaches RA. RP with, at least, four branches, without gradate series of crossveins visible. Crossvein between stems of RA and MA absent, the basalmost crossvein present (1rp-ma, also known as "basal piece of MA" or "b vein" in older nomenclatures) located almost immediately after the branching of the basal fork of RP, straight (not sinuous). Branching of MA and MP distad the basalmost branching of RP. Cubital and anal veins not preserved.
Abdomen barely preserved, ca. 4.20 mm long. Genitalia not preserved. www.nature.com/scientificreports www.nature.com/scientificreports/ Age and locality. San Just amber, northeastern Spain (Teruel Province) 50 . Dated as middle-upper Albian 51 , but most likely upper Albian according to new extensive, unpublished data on palynomorphs.
Etymology. Specific name is after Latin verb lacerare, meaning "to tear to pieces, to shatter, to destroy", in its feminine, singular participle perfect passive conjugation, referring to the fragmentary and disintegrated appearance of the holotype's body.

Remarks
The latest phylogenetic assessment of Mantispidae 11 established four apomorphic characters for the family: (1) pronotum elongate posterior to forecoxae 54 (Figs 5 and 6a); (2) pronotum tubular (ventrally fused) 54 (Fig. 6a); (3) foretibiae with prostrate setae 10,55 (lost in Mantispinae) (Figs 6c and 7c); and (4) meso-and metathoracic legs with third and fourth tarsomeres subequal in length 54 . The presence of prostrate setae on the foretibia (and the foretarsus) (Figs 3b and 4c) firmly accommodates the new fossil species within Mantispidae. The third and fourth tarsomeres of the meso-/metathoracic legs are subequal in length (Fig. 4d,e), although this character is rather subtle to assess and has not been evaluated in most fossil mantispoids with raptorial forelegs such as in paraberothines. The presence of a tubular pronotum and its elongation posterior to the forecoxae insertion cannot be assessed in the new species due to preservation. The absence of spine-like setae on the ventral side of the foretibia (and the foretarsus) further discards a relationship of the new fossil with paraberothines 19 , which lack prostrate setae (see discussion).
Multiple characters present in Aragomantispa lacerata gen. et sp. nov. rule out its affiliation to the mantispid subfamilies Symphrasinae, Calomantispinae, and Mantispinae, and suggest accommodation within the remaining mantispid subfamily, the Drepanicinae (although see below) 10,11 . These characters are: (1) absence of forefemur laterally compressed ventrally (presence is synapomorphic of Calomantispinae and Mantispinae), (2) combined length of foretibia and foretarsus about as long as that of forefemur (clearly shorter in Mantispinae), (3) pentamerous foretarsi (tetramerous foretarsi are apomorphic for Symphrasinae), (4) foretarsomere 1 not distally produced (distally produced in a claw-like process present, likely as an apomorphy, in Symphrasinae), (5) two www.nature.com/scientificreports www.nature.com/scientificreports/ pretarsal claws in all legs (one pretarsal claw on the prothoracic leg is apomorphic in Mantispinae) 11 , and (6) arolia present in all legs (absent in the prothoracic leg of Mantispinae). Nevertheless, the character states noted above are considered plesiomorphic for Drepanicinae, the monophily of which is supported by genitalic characters 11 , which are not assessable in the new fossil due to its fragmented condition.  2 mm), ratio IP length/modified seta length 1:2 to 1:5; D, minor size, ratio around 1:1 (ratios of 2:3 and 3:2 also present); E, major size (>0.2 mm), ratio ca. 1:1; F, major size, ratio 2:1; G, major size, ratio 3:1 to 7:1 (basalmost IP); H, mesomantispine spine-like structures (fine structure unknown due to fossilisation as compressions); I, large and thick spine-like seta; J-L, increasingly larger IPs bearing minute chitinous cones (Stitz organs). Foretibial and/ or foretarsal integumentary specialisations: i,v,vi, erect spine-like setae; ii,iii, mesomantispine prostrate seta and erect spine-like structure, respectively (fine structure unknown due to fossilisation as compressions); iv,vii,viii, prostrate setae (adpressed to the cuticle for all their length, distal stretch raised and running above the cuticle, or adpressed only at the tip, respectively). All integumentary specialisations at the same scale. Abbreviations: Pg -Palaeogene, Ng -Neogene. www.nature.com/scientificreports www.nature.com/scientificreports/ Three characteristics based on the arrangement and microstructure of the integumentary specialisations from the raptorial forelegs support the assignation of the new fossil to the Drepanicinae: (a) a combination of major IPs each bearing a modified seta, the basalmost being the largest and a few of such structures, yet smaller, more anteriorly placed, and numerous minor IPs each bearing a modified seta 55 (Figs 1b, 3a,c and 4a,b), (b) tarsal prostrate setae arranged in transverse pairs (not forming a single row as in Symphrasinae and Calomantispinae), and (c) foretibial and foretarsal prostrate setae having a different shape, with the latter being thicker, more raised and angulated (Figs 3b and 4c), a state detected in Theristria delicatula ( Fig. 6d; see types vii, viii in Fig. 8; see discussion) (foretibial and foretarsal prostrate setae shape subequal in Symphrasinae, Calomantispinae, and some Drepanicinae). Similarly, the preserved hind wing venation of the new fossil bears resemblance to that of extant drepanicines 10 , rather than to the other mantispid groups 10 , although that is likely a result of its plesiomorphic condition as well.
Some characters differ between A. lacerata and extant mantispids, including drepanicines. First, the shape of the scape is more elongate in the new species than in extant mantispids, where the scape is 1-2× longer than wide. This character is known to have a significant variability within the mantispoid groups (i.e., Berothidae, Rhachiberothidae), even among species treated as congeneric (see Rhachiberotha 15 ), with the greatest elongation degree (scape up to about 10-12× longer than wide) found in some paraberothines 15,44 . Other antennal characters, remarkably the number of flagellomeres in Mantispidae, show a high degree of intraspecific variation in extant taxa and are, therefore, not informative 10,55 . Second, the shape of the IPs differs from that present in extant mantispids in that instead of bearing minute Stitz organs on their tip, each bears a larger, modified thick seta that is 3.5-4× longer than wide basally (Fig. 4a). And lastly, although the tarsal prostrate setae have a very similar morphology than those present in some Theristria species as noted above, their distal stretch remains raised and running parallel above the cuticle instead of being inclined towards it. In any case, and in spite of these differences, the most conservative approach for now is to classify the new species within the subfamily Drepanicinae. Future findings of more complete fossil material related to the new taxon will clarify that stance. Note that whereas trichosors between veins are entirely lacking in most extant Drepanicinae, Calomantispinae, and Mantispinae 11 , they are present in multiple numbers along the anterio-distal wing margin in the drepanicine Gerstaeckerella Enderlein 10,54 and along the whole wing margin in Symphrasinae 56 . The presence of single trichosors between veins along the entire wing margin is shown by the new species and many other fossil mantispids 25,29,31 .
Within the fossil diversity of Mantispidae, A. lacerata is most similar to Doratomantispa burmanica, described from late Albian-earliest Cenomanian Burmese amber as a drepanicine 25 but currently considered of unknown familial relationships 11 . Interestingly, both species share the presence of forefemoral IPs bearing modified setae where the latter is about 4× longer than wide basally ( Fig. 4a; see type G in Fig. 8). This condition was not originally described but is discernible from the provided photographs 25 . However, among other characters, Aragomantispa gen. nov. differs from Doratomantispa in the forecoxae not as elongate, four major IPs on the forefemora (vs. six), presence of forefemoral minor IPs bearing modified (needle-like and thick) setae, foretibial prostrate setae (vs. peg-like protrusions), presence of prostrate setae on foretarsomeres 1-4, foretarsomere 1 among the shortest (vs. the longest), presence of arolium, and two (vs. 1) ra-rp crossveins before the pterostigmal area in the hind wing.
The placement of Micromantispa cristata, from Burmese amber and initially considered a mantidfly 26 , has raised controversy 19,27,57 . We agree with Makarkin 19,27 in that this taxon is more comfortably accommodated within the Paraberothinae, particularly due to the highly diagnostic presence of spine-like setae on the inner foretibia (and foretarsus), absent in mantidflies, and lack of prostrate setae. Note that "prostrate setae" were described from M. cristata's foretibia, but, surprisingly, from its dorsal surface instead of ventrally 26 . Judging from the photographs offered by the authors, their "prostrate" setae appear to represent the insertions of partly detached, regular setae from the dorsal surface of the foretibia. In any case, as Shi et al. noted 57 , it is paramount to keep unveiling diversity of fossil mantispoids with raptorial forelegs in order to elucidate their true relationships, including that of M. cristata.

Discussion
In praying mantises, the foreleg's spines not only act as physical structures to catch, hold, and direct prey deeper into the femorotibial junction, but some of these -the femoral hinged spines-are also mechanoreceptors that elicit the striking reflex and, once the prey is captured, sense its movements and keep the forefemur and the foretibia closed against each other 1,58 . The femora from the raptorial forelegs of extant mantispids are also equipped with a sophisticated, yet different, sensory equipment: modified setae borne by each spine-or tubercle-like integumentary process (IP) shape minute, partly invaginated chitinous cones 55,59,60 (Figs 6b, 7b,c; see types J-L in Fig. 8). These structures were named "Stitz organs" and described as mechanoreceptors hypothesised to derive from sensillae trichoidea based on neurohistological observations 60 . Stitz organs are also known to be present on the pronotum from some drepanicine mantidflies 10,11,55 . In extant symphrasine and drepanicine mantidflies, apart from the IPs bearing a Stitz organ (Figs 6b and 7b,c), other integumentary specialisations exist: long and thick spine-like setae (Lambkin's "long thick black setae" 10 ; see Tjeder, 1959: fig. 249 14 ), with bases of insertion that are globulose, are present in Symphrasinae (Fig. 7a,b; see type I in Fig. 8), whereas in extant Drepanicinae, although similar yet smaller spine-like setae with globulose bases of insertion can be present 55 , moderately elongate IPs each bearing a modified seta, with a ratio IP length/modified seta length of ca. 1:1, also exist ( Fig. 6b; see types B and D in Fig. 8).
Although the fine structure of the anteriorly directed, spine-like structures on the ventral side of the forefemora is relatively well known for extant mantispoids with raptorial forelegs, it has remained largely overlooked in fossils. This is particularly true in Paraberothinae, the disparity of forefemoral spine-like structures of which includes spine-like setae (type B in Fig. 8) and diverse types of IPs each bearing a modified seta. The latter differ in total size, ranging from about 0.05 to 0.3 mm, as well as in the relative length between the IP and the emerged www.nature.com/scientificreports www.nature.com/scientificreports/ portion of the modified seta that each bear distally. This includes IPs shorter than the modified seta (ratio IP length/modified seta length 1:2 to 1:5; type C in Fig. 8), IPs equal or subequal in length than the modified seta (ratio IP length/modified seta length around 1:1; types D and E in Fig. 8), and IPs longer than the modified seta (ratio IP length/modified seta length 2:1; type F in Fig. 8). In that regard, re-examination of the holotype of Eorhachiberotha burmitica shows how, in spite of not having been originally described likely due to bad preservation 43 , the specimen's forefemora are at least armed with a basal IP bearing a modified seta, with a length ratio between the two of ca. 1:1 (Fig. 7d). By contrast, the diversity of integumentary specialisations in crown Rhachiberothidae appears to be less disparate (types C-E in Fig. 8) 14,15 . Furthermore, in Dipteromantispidae, short and thick spine-like setae arranged in a few rows have been described from some forms (type A in Fig. 8), whereas in others there appears to be an absence of forefemoral integumentary specialisations 42,48,49 . The fine structure of the forefemoral "spines" of the mesomantispines remains unknown due to their preservation as rock compressions (type H in Fig. 8).
Prostrate setae refer to strong setae adpressed to the cuticle (i.e., not erect, recumbent) and with apices pointing anteriorly 10,14,54,55,61 (Figs 4c, 6c,d and 7c). These integumentary specialisations play a mechanical role in the raptorial function of mantidflies by creating a hardened edge towards which the spines of the forefemur slide along, creating a "scissor" effect 10 . As mentioned earlier, the presence of prostrate setae forming a closely-spaced lateroventral ridge ventrally on the foretibia is considered an apomorphy of Mantispidae that was lost in Mantispinae 11 ; in the latter, a sclerotised and acute longitudinal rim of the foretibial cuticle itself creates the hardened cutting edge instead 10 . Remaining mantispoid groups with raptorial forelegs lack prostrate setae on the foretibia, instead having spine-like setae (often also present on the foretarsi as well) (Paraberothinae) 16,17 (see types i, v, vi in Fig. 8) or no specialised setae at all in these leg segments (crown Rhachiberothidae and Dipteromantispidae) 14,42,48,49 . Moreover, prostrate setae are additionally present on the foretarsus of all mantispids but Mantispinae, but their location, arrangement and morphology is variable between these groups. In Symphrasinae, foretarsal prostrate setae are restricted to a longitudinal row on foretarsomere 1, which has a claw-like process distodorsally, and the prostrate setae morphology is the same than that present on the foretibia 14,54,56,59,62,63 . In Calomantispinae, foretarsal prostrate setae are present on foretarsomeres 1-4; those in foretarsomere 1 are arranged in a single row, and their morphology is essentially the same than those on the foretibia (although apparently slightly thicker for some species, such as Nolima victor) (Fig. 7c). In Drepanicinae, however, foretarsal prostrate setae are arranged on transverse pairs on foretarsomeres 1-4 10,11,55 (Fig. 6e), and the prostrate setae morphology can differ between those on foretibia and those on foretarsus (a circumstance not ascertainable from previous accounts 10,55,63 ). Indeed, in some Theristria species such as T. delicatula, prostrate setae on foretarsomeres 1-4, instead of being thin, gently curving and completely adpressed to the cuticle for all their length, they are thicker and have a basal stretch that is rather erect and a distal stretch abruptly inclined downwards, therefore being directed towards the cuticle (Fig. 6d). This condition resembles that present in Aragomantispa lacerata gen. et sp. nov., although in the latter the distal stretch of the foretarsal prostrate setae does not incline downwards so it remains raised running parallel above the cuticle (Fig. 4c). For other examined drepanicine species, however (T. storeyi, Allomantispa mirimaculata), morphology between foretibial and foretarsal prostrate setae is essentially the same. Moreover, in the Cretaceous mantidfly Doratomantispa burmanica, originally considered a drepanicine but the relationships of which were later considered enigmatic 11 , blunt peg-like (not setae-like) protrusions forming a discontinuous ridge on the inner foretibiae were described 25 . Even if these structures probably correspond to modified prostrate setae 11 , their morphology and arrangement significantly differ from those of the prostrate setae from extant mantispids. Lastly, prostrate setae have been described from the foretibiae and foretarsus of some mesomantispines, all preserved as compressions from Asia 18,21,22,31 ; as the fine structure and exact arrangement of these integumentary structures is unknown, their homology with those present in the new taxon (Fig. 4c) and extant mantispids (Fig. 6c-e) should remain contentious.
Comparison between integumentary specialisations from the different insect groups with raptorial forelegs provides some interesting insights. In praying mantises (Mantodea), the foreleg armature related to the raptorial function, apart from the foretibial spur, namely consists of modified (spine-like) setae (=spines) variable in number and development (multiple secondary reductions are known), and only a few taxa have spines that are inserted on elevated IPs (=socketed spines) 1 . Some Cretaceous mantises bear spines (allegedly articulated) on mid-and/or hind legs 53 , resembling the condition present in some plesiomorphic lineages of extant mantises such as Chaeteessa 1 . The fossil record of praying mantises reinforces the hypothesis that the spines on the mantodean foreleg originated from setae, and that the former are homologous with the setae from the blattodean (cockroach) foreleg 1 . In hemipterans, the raptorial forelegs of aquatic nepomorphan hemipterans (i.e., Belostomatidae, Gelastocoridae, Naucoridae, Nepidae, and Potamocoridae) usually show a lower degree of development of integumentary specialisations 3 . However, those present in assassin bugs (Reduvioidea) are widely diverse, including highly specialised structures such as the "fossula spongiosa" and the use of sticky secretions produced by specialised setae 2 . Even if the disparity of modified spine-like setae and IPs bearing modified setae from assassin bugs is comparable to that identified herein from extinct mantispoids, modified setae do not appear to be as reduced as the minute chitinous cones representing the Stitz organs in extant mantispids [64][65][66][67] . In true flies, thickened setae are present in raptorial forelegs of both empidid flies 5 and predaceous biting midges, the latter also showing moderately elevated IPs in some cases, including in some fossil forms 4,68 . Furthermore, in the genus Ochthera (Ephydridae) forefemora have an armature of thickened setae some of which are inserted on moderately elevated IPs; remarkably, Ochthera also shows prostrate setae (apparently in a single row) along the foretibial spur 6,69 , a condition highly resembling that present on the spur-like foretarsomere 1 of symphrasine mantispids 56 . Lastly, some staphylinid beetles have raptorial forelegs and show striking behaviour but it is the foretarsus that bears adhesive setae 7 .
Although prostrate setae are one of the few apomorphic characters of mantidflies, their fine structure had not been hitherto described from any fossil representative. Aragomantispa lacerata gen. et sp. nov. proves how (2019) 9:13248 | https://doi.org/10.1038/s41598-019-49398-1 www.nature.com/scientificreports www.nature.com/scientificreports/ Cretaceous mantidflies possessed types of prostrate setae comparable to those of their extant counterparts. On the other hand, the most widespread mechanism by which spine-like structures have developed in the forelegs of insects associated to the raptorial function is through the modification, namely enlargement and thickening, of setae. However, a different trend that has contributed to shape functional spines in some insect lineages with raptorial forelegs is the development of integumentary processes each of them elevating the modified setae. Although such structures are nowadays present in some reduviid, mantodean, and dipteran lineages, in no group they are as pervasive as in extant mantidflies, where modified setae reach their minimum size in the form of minute chitinous cones, or Stitz organs. It had been previously hypothesised that the Stitz organs were the result of the reduction of sensillae trichoidea. The findings presented herein provide palaeontological evidence in support of that hypothesis. In that regard, two character states of integumentary specialisations related to the raptorial function in the new species, i.e., (1) foretarsal prostrate setae distally raised and running parallel above the cuticle, and (2) major forefemoral integumentary processes each bearing a modified seta about 4× longer than wide basally (allegedly also present in Doratomantispa), could represent transitional stages between the plesiomorphic, more generalised (seta-like) conditions and those present in extant mantidflies, where (1) foretarsal prostrate setae are, at least distally, adpressed to the cuticle and (2) forefemoral integumentary processes bear Stitz organs. In any case, only a phylogenetic analysis including both raptorial and non-raptorial mantispoids once more fossil material is unearthed and studied will be able to ascertain the intermediate nature of these character states. The variability of integumentary specialisations from the ventral surface of the femora, tibiae, and tarsi from the raptorial forelegs of mantispoids showcased herein demonstrates the need to provide detailed descriptions of these structures -a practice that has been scarcely done in the past, particularly for fossils-in order to account for additional characters of potential phylogenetic significance. Fossils like A. lacerata are invaluable for providing data to help elucidate the complex evolutionary history of mantispoids, including that of the traits enabling the raptorial lifestyle.

Material and Methods
Taxa examination. The new fossil specimen was isolated within a small amber piece and prepared in Epoxy resin. A Discovery.V12 Zeiss stereomicroscope, and two compound microscopes (an Olympus BX51 and a Zeiss AXIO) were used to examine the specimens. The new fossil specimen was drawn using a camera lucida attached to the stereomicroscope and to the Olympus BX51 compound microscope. Specimens were photographed using an Axiocam 105 colour digital camera attached to both the stereomicroscope and the Zeiss AXIO. Series of images were taken with the software ZenPro v.2.3 and stacked using the software Helicon Focus v.6.8.0. This published work and the associated nomenclatural acts have been registered in ZooBank, the proposed online registration system for the International Code of Zoological Nomenclature. The ZooBank LSIDs (Life Science Identifiers) can be resolved and the associated information viewed through any standard web browser by appending the LSID to the prefix "http://zoobank.org/". The LSID for this publication is 93EF62A7-75C8-4916-A275-CEA9D22D91A3, and those of the associated nomenclatural acts are C12BCD59-8E2C-4C86-AF29-4D19BA9F4E7B (Aragomantispa gen. nov.) and B11B14A7-620A-4B6F-A19C-89F29DCADC7B (A. lacerata sp. nov.). (2019) 9:13248 | https://doi.org/10.1038/s41598-019-49398-1 www.nature.com/scientificreports www.nature.com/scientificreports/ of extant mantispids 55,60 . In that regard, the use of the term "spine", "teeth", "denticle", or "spine-like seta" 14,42,55 , among others, are far from being satisfactory. It is necessary to use a more precise terminology able to account for the disparity present in deep time Mantispoidea and identified herein. Thus, it is proposed to use the descriptive term "integumentary process (=IP) bearing a modified seta" for the forefemoral structures comprising a more or less elevated integumentary base (=pedestal, socket) shaping an elongate truncate cone or a rounded tubercle, on the tip of which a thickened and variably elongate seta is inserted (e.g., see Tjeder, 1959: fig. 232 14 and Poivre's works 55,60 ). The term "spine-like seta" is restricted herein to modified seta inserted on regular (globular) bases, not on elevated IPs (contra Makarkin 19 ). We refrain to use the term "cuticular spines" used by Lambkin 10 for the IPs where the modified setae correspond to minute chitinous cones named Stitz organs of extant mantispids as they can be interpreted as structures fully composed of leg cuticle, i.e., not bearing any structure derived from setae.
Although still a matter of contention, herein Rhachiberothidae are considered a separate family 15 following the latest phylogenetic analyses where they have been recovered as a lineage distinct from Berothidae and Mantispidae 11,71 (although see Winterton et al. 72 ). Furthermore, Paraberothinae Nel, Perrichot, Azar & Néraudeau, 2005 is considered a valid taxon following the works of Makarkin and Kupryjanowicz as well as Makarkin's 19,39 but within Rhachiberothidae (instead of Berothidae) following Nel et al. 16 and more recent works that have considered the fossil forms classified within Paraberothinae as rhachiberothids 11,73 . Acknowledging that the current paraberothine diversity would appear to represent a grade leading to extant rhachiberothids and pending for a phylogenetic analysis where paraberothines are included, the group is tentatively regarded herein as sister to the Rhachiberothinae (=crown Rhachiberothidae).