A new lineage of Cretaceous jewel wasps (Chalcidoidea: Diversinitidae)

Specimens

Four specimens in four different pieces of Burmese amber were examined. Burmese amber is of Upper Cretaceous origin, approximately 99 my old (Shi et al., 2012). Additional information about the geographical origin of the individual pieces is not known. All pieces are deposited in the amber collection of the State Museum of Natural History, Stuttgart, Germany (SMNS).

Imaging

Imaging was done, using a MZ 16 APO Leica^® microscope, with an attached DXM 1200 Leica^® camera. The images were generated by stacking single images using the Automontage^® technique and the program Helicon Focus Pro^® (Vers. 6.7.1; Helicon Soft, Kharkov, Ukraine). For additional and detail imaging as well as measurements the digital microscopes Keyence VHX 600 and VHX 5000 were used. Adobe Photoshop^® CS4 Version: 11.0.2 was used to process all images. Drawings were made, using a camera lucida on a Leica^® M205 C microscope. Digitalization of the drawings and arrangement of the image plates was done with Adobe Illustrator^® CS4 (Version: 14.0.0).

Terminology

Terminology follows the Hymenoptera Anatomy Ontology (HAO) (Yoder et al., 2010). Abbreviations listed in Table 1 are used throughout the text and illustrations.

Cladistic analysis

Morphological cladistic analyses were performed using the 233 characters from Heraty et al. (2013). Their comprehensive matrix, encompassing 19 families, 78 subfamilies, 268 genera and 283 species of Chalcidoidea was used as basis for the here conducted phylogenetic analysis. Due to preservation and inaccessibility, some characters could not be scored for the fossils without reasonable doubt and were marked as unknown “?” (Appendix S1). Analyses were conducted using the program TNT ver. 1.5 (Goloboff, Farris & Nixon, 2008) following Heraty et al. (2013) in analysis setup. A sectorial search, with equally weighted characters, under New Technology methods was performed, using a ratchet weighting probability of 5% with 50 iterations, tree-drifting of 50 cycles, tree-fusing of five rounds and a best score hit of 10 times. New Technology searches in TNT provide refined algorithms more effective than simple branch swapping techniques applied in traditional searches, leading to shorter analyze times, especially in large datasets (Goloboff, Farris & Nixon, 2008). Nevertheless, traditional searches with and without implied weighting were conducted as well to test consistency of the results. Dependent on the used concavity constant (k), implied weighting aims to decrease the phylogenetic impact of supposed homoplasious characters, in comparison to equal weighting, (Congreve & Lamsdell, 2016). Morphological datasets of Chalcidoidea are reported to include a multitude of potentially homoplasious characters (Krogmann & Vilhelmsen, 2006; Heraty et al., 2013), therefore implied weights of k = 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 were used with 1,000 replications and Tree Bisection and Reconnection (TBR) for the analyses.

Nomenclature

The electronic version of this article in Portable Document Format (PDF) will represent a published work according to the International Commission on Zoological Nomenclature (ICZN), and hence the new names contained in the electronic version are effectively published under that Code from the electronic edition alone. This published work and the nomenclatural acts it contains have been registered in ZooBank, the online registration system for the ICZN. 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: LSID urn:lsid:zoobank.org:pub:B936D52D-7165-47CE-9C3E-0B79A17AC5AC. The online version of this work is archived and available from the following digital repositories: PeerJ, PubMed Central and CLOCKSS.

Systematic Paleontology

Type genus. Diversinitus gen. n.

Diagnosis. Antenna 13-segmented in male (Figs. 1B–1D, 2A, 3A and 3B) and female (Figs. 4C, 4E and 5A), with eight funiculars and 3-segmented clava, including a distinct terminal button; all funiculars (including F1) with multiporous plate sensilla (Figs. 1C, 4C and 4E). Eyes large, without pilosity, inner margins not divergent ventrally (Figs. 1B and 4B). Occipital carina absent. Labrum exposed below clypeus (Figs. 1B and 4B), semicircular, flap-like with setae at least at apical margin, broadly contiguous with clypeal margin. Mandibles two toothed (Figs. 2A and 3A). Pronotum lacking collar (Figs. 3A, 5A and 5B). Mesosoma with independent, large and triangular, laterally exposed prepectus (Figs. 3A, 5A and 5B). Mesothoracic spiracle situated at lateral margin of mesoscutum, at juncture of pronotum and prepectus. Mesonotum with notauli deep and complete (Figs. 1D, 3B, 5A and 5B). Mesoscutellum with frenum distinguishable (Figs. 1D, 3B and 4F). Mesopleuron concave with acropleuron not enlarged. Fore wing with short marginal fringe. Basal vein at least apically pigmented (Figs. 1E and 4A). Uncus elongate, bent in direction of postmarginal vein (Figs. 1E, 4A and 4D). Postmarginal vein distinctly longer than marginal vein (Figs. 1E, 4A and 4D). Hind wing normal, membrane extending to base of wing, three hamuli, first straight (Figs. 1E and 4A). Tibial spur formula 1:1:2; protibial spur slightly curved, slender, simple tip; mesotibial spur slender and straight. Tarsus on all legs five segmented. Metasoma with Mt₈ and Mt₉ fused into syntergum (Mt₈₊₉) in both sexes (Figs. 3A, 3B, 5A and 5B). Cercus peg-like (Figs. 3A, 5A and 5B).

Key to species of Diversinitidae

Type species. Diversinitus attenboroughi sp. n.

Diagnosis. Antenna inserted in lower third of face (Fig. 1B). Clypeus transverse. Scape ventrally expanded (Figs. 2A and 3A). Pronotum less than 1/4 length of mesoscutum (Figs. 1D and 3B). Axilla not advanced. Frenum anteriorly delimited by deep frenal groove (Figs. 1D and 3A). Fore wing completely pilose, i.e., speculum absent (Fig. 1E), basal vein only anteriorly pigmented. Gaster distinctly petiolate (Fig. 1D).

Etymology. The generic name Diversinitus is composed of two parts. The first being “Divers-”, originating from the Latin adjective “diversus”, meaning diverse or different. The second part, “-initus”, is the Latin noun “initus” translating to “origin” or “start”. Together the two parts can be translated to “origin of diversity”, referring to the age of the fossil and the diversity which evolved since its appearance in the Upper Cretaceous. The generic name is masculine in gender.

Diagnosis. As for the genus.

Male. Measurements: (h), holotype; (p), paratype. Total body length, excluding protruded aedeagus 1.67 mm (h), metasoma of paratype destroyed.

Head. In frontal view oval, bare, broader than rest of body, breadth 0.41 (p)–0.52 mm (h), height 0.34 mm (h), length in dorsal view 0.23 (p)–0.29 mm (h). Foramen magnum situated higher than half height of head. Eye length 0.25 mm (h), height 0.28 mm (h), distance between eyes 0.21 (p)–0.23 mm (h). Transfacial sulcus indiscernible. Antennal scrobes probably shallow. Clypeus transverse, apically truncate, tentorial pits absent, dorsal margin straight. Mandible at least two times as long as broad with slight curvature and few short setae on outer surface. Maxillary palps with at least three segments. Labial palps with at least two segments. Malar space shorter than 1/3 length of an eye.

Antenna. Inserted in lower third of face, hardly above ventral level of eyes, with toruli closer to edge of eyes than to each other. Scape ventrally expanded and broadened over most of its length, not reaching median ocellus. Pedicel length, measured laterally, 0.05 (h)–0.06 mm (p) and breadth 0.04 mm (h, p). F1 subquadrate, fully developed (not anelliform); following funiculars increasingly more transverse and broadening distally, F1–F4 with sides diverging (subconical), F5–F8 more parallel sided (cylindrical) and asymmetrically formed, connections between segments rather slanted; F1 dorsolateral length (mm): width (mm) = 0.03(p)–0.04 (h): 0.03 (p)–0.04 (h), F2 = 0.02 (h, p): 0.04 (h, p), F3 = 0.02 (p)–0.03 (h): 0.04 (h, p), F4 = 0.2 (p)–0.03 (h): 0.04 (h, p), F5 = 0.03 (h, p): 0.04 (h, p), F6 = 0.03 (h, p): 0.04 (h, p), F7 = 0.03 (p, h): 0.04 (p)–0.05 (h), F8 = 0.03 (p)–0.04 (h): 0.04 (p)–0.05 (h). Clava differentiated, sutures rather straight; F9 length (mm): width (mm) = 0.03 (h, p): 0.04 (p)–0.05 (h), F10 = 0.02 (h, p): 0.03 (p)–0.04 (h), F11 + F12 = 0.02 (p)–0.04 (h): 0.02 (p)–0.03 (h).

Mesosoma. Length 0.60 (p)–0.74 mm (h), arched. Pronotum bare, posteriorly deeply emarginated, u-shaped, medially much shorter (0.06 (p)–0.07 mm (h)) than mesoscutum (0.25 (p)–0.27 mm (h)), regularly reticulate. Prepectus slightly convex, lightly sculptured, with thin shiny rim along its dorsal and posterior margin. Tegula much smaller than prepectus. Mesonotum finely regularly reticulate and with very sparse, short pilosity. Mesoscutum slightly shorter than wide; notauli reaching transscutal articulation, widely separated posteriorly. Mesoscutellum length 0.23 (p)–0.26 mm (h), with frenum delimited anteriorly by deep frenal groove (length: 0.05 (p)–0.06 mm (h)); axillae not advanced, widely separated at transscutal articulation. Metapleuron small, bare. Metanotum length 0.06 (p)–0.07 mm (h), with smooth metascutellum not reaching anterior margin of metanotum, lateral panel foveolate. Propodeum transverse, rectangular, slightly arched, length 0.09 (p)–0.11 mm (h), with coarse irregular sculpture, lateral propodeal callus bare; spiracles round to slightly elliptical.

Wings. Fore wing hyaline, immaculate, entirely pilose; humeral plate with at least three setae; basal vein apically pigmented and angled relative to submarginal vein at about 10–15°; marginal vein slightly thickened relative to postmarginal vein; stigmal vein about 0.5 times length of marginal vein; uncus bent at angle of about 95–100° in direction of postmarginal vein, almost reaching it; postmarginal vein not reaching apex of wing, 1.5 times as long as marginal vein. Hind wing apical 2/3 pilose, rest relatively bare; posterior marginal fringe moderately long.

Legs. Pro- and metacoxa larger than mesocoxa; metacoxa dorsally bare, except few hairs posteriorly. Protibial setae inconspicuous and short. Basitarsal comb not visible. Metatibia laterally flattened, bearing two spurs, one robust, the other short and more slender.

Metasoma. Petiole (Mt₁) cylindrical distinct and reticulate, length 0.09 mm (h), breadth 0.06 mm (h). Gaster of holotype 0.66 mm in length, lanceolate; terga smooth and bare except of Mt₆–Mt₈₊₉ with longitudinal rugosity and lateral setae, hindmargins straight, length of terga of holotype: Mt₂: 0.24 mm, Mt₃: 0.07 mm, Mt₄: 0.07 mm, Mt₅: 0.07 mm, Mt₆: 0.11 mm, Mt₇: 0.06 mm, Mt₈₊₉: 0.04 mm. Cerci peg-like with few long setae.

Female. Unknown.

Specimen examined. Male holo- (SMNS Bu-4) and paratype (SMNS Bu-5) deposited in the SMNS. The amber piece hosting the holotype also includes syninclusions: three complete Diptera and three further Diptera, which are preserved only in part. Additionally, a Serphitidae (Hymenoptera) is included in the same piece. The amber piece including the paratype also hosts a Platygastridae: Scelioninae (Hymenoptera).

Etymology. Named after the well renowned British broadcaster and naturalist Sir David Frederick Attenborough for his inspiring enthusiasm and devotion to natural sciences. This species was dedicated to Sir Attenborough during his visit to the SMNS on the occasion of his 91st birthday.

Type species. Burminata caputaeria sp. n.

Diagnosis. Foramen magnum situated at lower third of head (Fig. 4A). Tentorial pits deep (Fig. 4B). Clypeus transverse (Fig. 4B). Pronotum only slightly shorter than mesoscutum (Fig. 5A). Axilla slightly advanced (Fig. 5A). Fore wing with speculum; basal cell bare; basal vein almost completely pigmented (Fig. 4A). Posterior fringe on hind wing long (Fig. 4A). Ovipositor protruding about half length of gaster (Fig. 4A).

Etymology. The generic name is composed of two parts. The first part “Burmi-”, references the origin of the amber piece whereas the second part, “–nata”, originates from the Latin adjective “natus” translating to “born”. The generic name is feminine in gender.

Diagnosis. As for the genus.

Female. Total body length, excluding protruding ovipositor 1.23 mm.

Head. In frontal view oval, bare, much broader than rest of body, breadth 0.40 mm, height 0.23 mm, dorsal length not measurable. Foramen magnum situated at lower third of head. Eye length 0.17 mm, height 0.16 mm, distance between eyes 0.22 mm. Putative transfacial sulcus anterior to antennal scrobes length 0.10 mm. Antennal scrobes absent. Clypeus transverse, apically truncate, laterally delimited by large tentorial pits, dorsal margin straight. Mandible about 1.6 times as long as broad, rather straight, setae not distinguishable. Maxillary palps with at least three segments. Labial palp segments not countable. Malar space more than 1/3 length of an eye.

Antenna. Inserted at about center of face, at half height of eyes, with toruli slightly closer to edge of eyes than to each other. Scape slender, not flattened, not reaching median ocellus. Pedicel length, measured laterally, 0.04 mm and breadth 0.04 mm. F1 subquadrate, subconical, fully developed (not anelliform); following funiculars transverse to quadrate, conical, connections between segments rather slanted; F1 lateral length (mm): width (mm) = 0.03: 0.04, F2 = 0.03: 0.04, F3 = 0.03: 0.04, F4 = 0.04: 0.04, F5 = 0.04: 0.04, F6 = 0.04: 0.04, F7 = 0.04: 0.04, F8 = 0.04: 0.04. Clava differentiated, sutures oblique, F9 length (mm): width (mm) = 0.04: 0.04, F10 = 0.03: 0.04, F11 + F12 = 0.03: 0.03.

Mesosoma. Length 0.49 mm, weakly arched. Pronotum bare except of few long setae on hind margin, posteriorly slightly emarginated, medially only slightly shorter (0.12 mm) than mesoscutum (0.15 mm), regularly finely reticulate. Prepectus convex, lightly sculptured, with thin shiny rim along its dorsal and posterior margin. Tegula much smaller than prepectus. Mesonotum, finely regularly reticulate, largely bare, only few single setae on lateral lobe of mesoscutum, msoscutellum and axilla. Mesoscutum breadth not measurable; notauli reaching transscutal articulation, widely separated posteriorly. Mesoscutellum length 0.14 mm, with frenum short (0.02 mm), delimited anteriorly by shallow frenal groove; axillae slightly advanced, widely separated at transscutal articulation. Metapleuron small and triangular, bare. Metanotum and propodeum hardly discernable because of cracked amber and air inclusions, propodeum apparently arched.

Wings. Fore wing hyaline, immaculate, speculum present, basal cell bare, costal cell pilose throughout; humeral plate with at least two setae; basal vein almost completely pigmented, angled relative to submarginal vein at about 27°; marginal vein as thick as postmarginal vein; stigmal vein about 0.4 times length of marginal vein; uncus bent at angle of about 110° in direction of postmarginal vein, almost reaching it; postmarginal vein not reaching apex of wing, 1.6 times as long as marginal vein. Hind wing apical 2/3 pilose, rest relatively bare; posterior marginal fringe long.

Legs. Pro- and mesocoxa about same size, metacoxa slightly larger, dorsally completely bare. Protibial setae inconspicuous and short. Basitarsal comb not visible. Metatibia hardly flattened, bearing two equally short and robust spurs.

Metasoma. Petiole (Mt₁) indistinct. Gaster lanceolate, length excluding ovipositor 0.52 mm; terga smooth and bare except dorsal surface of Mt₇ and Mt₈₊₉ with longitudinal rugosity, hindmargins straight, length of terga: Mt₂: 0.12 mm, Mt₃: 0.04 mm, Mt₄: 0.04 mm, Mt₅: 0.05 mm, Mt₆: 0.06 mm, Mt₇: 0.11 mm, Mt ₈₊₉: 0.09 mm. Cercus peg-like, appearing to be slightly spatulate, arising from under syntergum, bearing at least three setae. Hypopygium folded downwards, slightly longer than half of gaster. Ovipositor protruding about half length of gaster, third valvulae broad.

Male. Unknown.

Specimen examined. The holotype (SMNS Bu-304) is deposited in the SMNS. Besides the holotype the amber piece also includes two Diptera and one Platygastridae: Scelioninae (Hymenoptera), amongst parts of other insects.

Etymology. The specific epithet “caputaeria” consists of two parts originating from the Latin noun for “head” (caput) and the adjective for “towering up” (aerius), referring to the lowly situated foramen magnum, leaving the head protruding especially high over the pronotum. The species name is treated as an adjective.

Type species. Glabiala barbata sp. n.

Diagnosis. Head densely pilose, with mouth margin surrounded by especially long setae (Figs. 4D and 5B). Clypeus quadrate. Toruli situated at about center of face, closer to each other than to margin of eyes. All funiculars rather thistle shaped (Fig. 4E). Pronotum and mesonotum with dense, short pilosity (Fig. 4F). Pronotum about 1/3 the length of the mesoscutum (Figs. 4G and 5B). Axillae advanced about 1/4 the length of the mesoscutum (Fig. 4G). Frenum large, delimited by deep frenal groove (Fig. 4F). Lateral propodeal callus with dense pilosity. Fore wing with speculum (Fig. 4D); basal cell pilose, basal vein only anteriorly pigmented. Metacoxa dorsally with short pilosity. Ovipositor hardly protruding apex of gaster (Fig. 4D).

Etymology. The name consists of two parts originating from the Latin words for “hairless” (glabellus) and “wing” (ala), referring to the distinct speculum on the wing of the specimen. The generic name is feminine in gender.

Diagnosis. As for the genus.

Female. Total body length, excluding protruding ovipositor: 2.21 mm.

Head. Frontal view largely blocked, appearing trapezoid, finely pilose, except quite long pilosity on gena and mouth margin, about as broad as body, actual breadth and height not measurable. Foramen magnum situated higher than half height of head. Eye length 0.23 mm, height 0.27 mm, distance between eyes not measurable. Transfacial sulcus not discernable. Antennal scrobes absent. Clypeus quadrate with subparallel sides, apically truncate, tentorial pits absent, dorsal margin straight. Mandible not measurable, appearing broad and straight, with numerous longer setae on its outer surface. Maxillary palps probably with four segments. Labial palps with at least two segments. Malar space about 1/3 length of an eye.

Antenna. Inserted at about center of face (direct frontal view blocked), slightly below half height of eyes, with toruli closer to each other than to eyes. Scape slightly broadened, not reaching median ocellus. Pedicel lateral length not assessable. F1 subconical fully developed (not anelliform), distal funiculars more transverse, F2–F8 appearing thistle-shaped, with F2–F7 asymmetrically shaped, connections between segments rather slanted; F1 lateral length (mm): width (mm) = 0.05: 0.05, F2 = 0.06: 0.05, F3 = 0.05: 0.05, F4 = 0.06: 0.05, F5 = 0.05: 0.05, F6 = 0.05: 0.06, F7 = 0.05: 0.06, F8 = 0.05: 0.06. Clava not clearly differentiated, segments separated by deep, rather straight sutures, F9 length (mm): width (mm) = 0.04: 0.05, F10 = 0.05: 0.05, F11 + F12 = 0.05: 0.04.

Mesosoma. Length 0.96 mm, weakly arched. Pronotum densely shortly pilose, posteriorly deeply emarginated, u-shaped, medially much shorter (0.12 mm) than mesoscutum (0.4 mm), regularly reticulate. Prepectus almost flat, lightly sculptured, view on rim not clear. Tegula smaller than prepectus. Mesonotum regularly reticulate and densely, shortly pilose. Mesoscutum about 2/3 as long as wide; notauli reaching transscutal articulation, widely separated posteriorly. Mesoscutellum length 0.31 mm, with frenum delimited anteriorly by deep frenal groove (length: 0.07 mm); axillae strongly advanced, about 1/4 length of mesoscutum, widely separated at transscutal articulation. Metapleuron small and triangular, with few scattered setae. Metanotum length 0.06 mm, with smooth metascutellum not reaching anterior margin of metanotum, lateral panels prominent, foveolate. Propodeum transverse, rectangular, relatively flat, length 0.11 mm, reticulation regular, lateral propodeal callus with dense and long pilosity; spiracles round to slightly elliptical.

Wings. Fore wing hyaline, immaculate, speculum present, basal cell pilose, costal cell pilose throughout; humeral plate with at least two setae; basal vein apically pigmented and angled relative to submarginal vein at about 9°; marginal vein slightly thickened relative to postmarginal vein; stigmal vein about 0.4 times length of marginal vein; uncus bent at angle of about 95° in direction of postmarginal vein, almost reaching it; postmarginal vein not reaching apex of wing, 1.6 times as long as marginal vein. Hind wing apical 1/2 densely pilose, the rest relatively bare; posterior marginal fringe short.

Legs. Pro-, meso- and metacoxa about same size, metacoxa dorsally with short pilosity. Protibia with stout setae on anterior margin, other setae more inconspicuous. Basitarsal comb longitudinal. Metatibia laterally flattened bearing two slender spurs, subequal in length.

Metasoma. Petiole (Mt₁) indistinct. Gaster lanceolate, length excluding ovipositor 0.98 mm; terga smooth and bare, hindmargins straight, length of terga: Mt₂: 0.21 mm, Mt₃: 0.09 mm, Mt₄: 0.15 mm, Mt₅: 0.18 mm, Mt₆: 0.14 mm, Mt₇: 0.11 mm, Mt₈₊₉: 0.1 mm. Cercus peg-like, club-shaped, arising from under syntergum, bearing at least three setae. Hypopygium folded downwards, slightly longer than 2/3 of the gaster. Ovipositor protruding about length of Mt₈₊₉, third valvulae broad.

Male. Unknown

Specimen examined. Female holotype (SMNS Bu-303) deposited in the SMNS. The piece of amber was cut to reveal a better view of the specimen. Both pieces are free of other inclusions.

Etymology. The specific epithet “barbata” is the feminine form of the adjective “barbatus” which means “bearded” and refers to the setose lower face of the specimen. The species name is treated as an adjective.

Taxonomic remarks

It may seem counterintuitive to place the only two known males of Diversinitidae in a separate genus than the two females, especially since sexual dimorphism is widely spread in Chalcidoidea, most notably in Agaonidae and Eupelmidae resulting in a separation of sexes in morphological analysis of females and males, when coded separately (Krogmann & Vilhelmsen, 2006; Heraty et al., 2013). In most other chalcidoids however, those modifications do not include severe changes to the body plan and are often confined to body size (Hurlbutt, 1987) and antennal characters (Barlin & Vinson, 1981). Males of D. attenboroughi differ from both known females of Diversinitidae by the absence of a speculum on the forewing (versus presence of speculum), an elongate petiole (versus a transverse petiole) and an antennal insertion in the lower 1/3 of the face (versus an insertion near center of face). In addition, they also lack each of the diagnostic characters of the other two females (see below) so that a separate generic placement seems to be justified.

Furthermore, we consider the two females as not congeneric based on significant morphological differences: Glabiala barbata differs from B. caputaeria in having the foramen magnum situated higher than half the height of the head (versus lower third of head), a pronotum only 1/3 length of mesoscutum (versus slightly shorter than mesoscutum), distinctly advanced axillae (versus slightly advanced), a large and clearly anteriorly delimited frenum (versus short and shallowly delimited) and a pilose basal cell on the forewing (versus a bare basal cell).

Results of cladistics analyses

The new technology analysis in TNT found 39 most parsimonious trees (5,395 steps) with the strict consensus tree being 5,861 steps long. The general topology of Heraty et al. (2013) could largely be retrieved (Fig. 6). As in Heraty et al. (2013) the following families appeared as monophyletic: Agaonidae, Chalcididae, Encyrtidae, Eurytomidae, Leucospidae, Mymaridae, Rotoitidae, Signiphoridae, Torymidae (including Megastigminae) and Trichogrammatidae. Contrary to Heraty et al. (2013), Aphelinidae and Eucharitidae could be retrieved as monophyletic as well. In the unweighted new technology analysis Mymarommatoidea was nested within Chalcidoidea as part of a larger clade containing the chalcidoid families Aphelinidae, Mymaridae, Rotoitidae and Signiphoridae, as well as few members of Tetracampidae and Eulophidae. Leucospidae were recovered as sistergroup to all other Chalcidoidea, including Mymarommatoidea. The fossils were recovered as a monophyletic group with Micradelus rotundus Walker, 1834 as sister taxon, nested within a large polytomy. Monophyly of the fossils could be retrieved in all analyses, however general tree topology changed considerably between different analyses. Using a traditional search without implied weighting (Appendix S2), Diversinitidae were recovered as sistergroup of all other Chalcidoidea with the inclusion of Mymarommatoidea. Mymaridae as well as Rotoitidae clustered in deeper clades far from the base of the tree. Using a traditional search with implied weights (Appendix S2), Mymarommatoidea were almost always recovered as sistergroup of Chalcidoidea (except k = 45), but topology changed drastically with increasing k value, as did the position of the fossils within the tree. In most analyses with k values below 30, the fossils were closely affiliated with the pteromalid genera Habritys brevicornis (Ratzeburg, 1844), Cheiropachus quadrum (Fabricius, 1787) and other interchanging groups. Above a k of 30, M. rotundus was recovered as a sistertaxon (k = 35 and 55) or only Cheiropachus quadrum (k = 40), Diversinitidae were sister to all Chalcidoidea including Mymarommatoidea (k = 45) or they were recovered close to Platynocheilus cuprifrons (Nees, 1834) and some Ormocerinae (k = 50 and 60).