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International audience; Examination of Hkamti and Tanai Burmese ambers reveals two new genera and species of †Lancepyrinae: Protopyris myanmarensis Jouault & Nel gen. et sp. nov. and Burmapyris azevedoi Jouault, Perrichot & Nel gen. et sp. nov. Protopyris Jouault & Nel gen. nov. is the first Bethylidae described from amber of the Hkamti deposit (lower Albian, mid-Cretaceous) in Myanmar. These specimens provide useful clues to understand the paleobiogeographic evolution of the †Lancepyrinae, since they are only predated by genera described from Lebanese and Spanish amber. These new taxa suggest a major paleobiogeographic scenario, since Burmese amber was probably produced on an island that separated from Gondwana during the Late Jurassic to Early Cretaceous. It thus suggests a possible earlier origin for the †Lancepyrinae, and thereby for the Bethylidae, in the Late Jurassic to earliest Cretaceous.

International audience; Examination of fossil ant specimens from various private and institutional German collections of Baltic amber has revealed a new genus and species of Myrmicinae, described here as Thanacomyrmex hoffeinsorum gen. et sp. nov. The new worker morphotype shares some similarities with the coeval extinct genus Parameranoplus Wheeler, also from Baltic amber, and the extant genera Pristomyrmex Mayr and Acanthomyrmex Emery, suggesting placement of the new fossil in the Myrmecina genus-group within the tribe Crematogastrini. The new genus highlights the tremendous diversity of ants that evolved in the Palaeogene European forests and composed the first major radiation of crown-group ants.; L’examen de fourmis fossiles dans diverses collections privées et institutionnelles allemandes d’ambre balte a révélé un nouveau genre et une nouvelle espèce de Myrmicinae, décrits ici comme Thanacomyrmex hoffeinsorum gen. et sp. nov. Ce nouveau morphotype d’ouvrière partage des similitudes avec le genre éteint Parameranoplus Wheeler, également connu de l’ambre balte, et les genres actuels Pristomyrmex Mayr et Acanthomyrmex Emery, suggérant le placement du nouveau fossile dans le groupe de genres Myrmecina, parmi la tribu Crematogastrini. Le nouveau genre souligne la grande diversité de fourmis ayant évolué dans les forêts paléogènes d’Europe et constituant la première radiation majeure du groupe couronne des fourmis.

The Zhangpu biota provides a new insight into biodiversity redistribution during the Mid-Miocene Climatic Optimum., During the Mid-Miocene Climatic Optimum [MMCO, ~14 to 17 million years (Ma) ago], global temperatures were similar to predicted temperatures for the coming century. Limited megathermal paleoclimatic and fossil data are known from this period, despite its potential as an analog for future climate conditions. Here, we report a rich middle Miocene rainforest biome, the Zhangpu biota (~14.7 Ma ago), based on material preserved in amber and associated sedimentary rocks from southeastern China. The record shows that the mid-Miocene rainforest reached at least 24.2°N and was more widespread than previously estimated. Our results not only highlight the role of tropical rainforests acting as evolutionary museums for biodiversity at the generic level but also suggest that the MMCO probably strongly shaped the East Asian biota via the northern expansion of the megathermal rainforest biome. The Zhangpu biota provides an ideal snapshot for biodiversity redistribution during global warming.

International audience; Amber, a natural polymer, is fossil tree resin derived from diverse botanical sources with varying chemical compositions. As such, all amber is susceptible to the effects of light, temperature, relative humidity, and oxygen, as well as exposure to certain chemicals, and will deteriorate over time in collections if left unprotected. Here we review approaches for the conservation, preparation, and imaging of amber specimens and their inclusions, and address indications and causes of amber degradation, as well as recommendations for a suitable storage environment. We also provide updated preparation and embedding protocols, discuss several techniques for imaging inclusions, and address digitization efforts. A stable storage environment is essential to mitigate or avoid deterioration of amber, which often manifests as crazing, spalling, breaking and colour changes. Based on previous conservation studies of fossil resins, we generally recommend storage in a climate-monitored environment with a relative humidity of ca. 50%, 18 °C, and stress that light exposure must be kept to a minimum. For stabilization and anoxic sealing, amber specimens should ideally be embedded in an artificial epoxide resin (EpoTek 301-2 or similar is currently recommended). Amber should not be treated with or stored in vegetable or mineral oils (even for a short time for examination or photography), or come into contact with alcohol, disinfecting agents, hydrogen peroxide, or other destructive solvents or mixtures, since any of these materials can irreversibly damage the amber. Most photography of inclusions for research and digitization purposes can be successfully accomplished using light microscopy. Scanning electron microscopy (SEM) is sometimes used to uncover fine details, but is an invasive method. However, X-ray based methods (utilizing micro computed tomography, or micro-CT) are becoming more frequently used and increasingly indispensable in the examination of minute internal structures of inclusions, and to fully visualize important structures in opaque amber. Micro-CT makes it possible to digitize an inclusion three-dimensionally, and thus enables digital specimen ‘loans.’ Light microscopal images are still widely used in the digitization of amber specimens and are an essential alternative to micro-CT imaging when resources or time are limited. Overall, due to the vulnerability of all fossil resins, we recommend that conservation of amber samples and their inclusions be prioritized.

International audience; A new genus and species of orussoid wasps, Cretorussus vilhelmseni gen. et sp. nov., is described based on new material from the mid-Cretaceous Burmese amber. Its wing venation and body characters lead us to emend the diagnosis of the family Burmorussidae. Cretorussus vilhelmseni gen. et sp. nov. is considered to be a specialized parasitic wasp of wood-living hosts because of the orussid-like ocellar crown, antennae attached well above clypeus, and antennal grooves absent. Interestingly, the third tarsomere carries a prominent lanceolate lobe, serving as part of the host detection. We propose a summary of the orussoid fossil diversity. Lastly, we discuss the implications of several characters of Burmorussidae that are involved in host detection.

International audience; Christophus myanmarensis gen. et sp. nov., Christophus ohmkuhnlei gen. et sp. nov., and Mintara parva gen. et sp. nov., three new species and two new genera of belytine wasps (Diapriidae: Belytinae) are described and figured from males preserved in mid-Cretaceous Kachin (Burmese) amber. These new fossils enrich the fossil record of Cretaceous diapriids, summarized here, demonstrating the diversity of the family before the K/Pg extinction and suggesting an older origin for the family.

A new species of drywood termite (Isoptera: Kalotermitidae) is described from a nearly complete alate specimen preserved in early Miocene Ethiopian amber. Glyptotermes abyssinicus new species is distinguished by its U-shaped head with 12-segmented antennae, the ocelli separated from the eye margin, the right mandible with an obtuse angle between the apical and first marginal teeth, the left mandible with an obtuse angle between the apical and first + second marginal teeth, and the wing venation. This is the first termite reported from Ethiopian amber, and the fourth Miocene species of the extant genus Glyptotermes Froggatt, 1897, together with species previously described from diatomites of China and amber from the Dominican Republic. As the oldest report of the genus known from Africa, G. abyssinicus n. sp. constitutes an interesting new record for the biogeographical history of the kalotermitid lineage.UUID: http://zoobank.org/7670b045-fb31-4809-8116-4d14c4dd275b

International audience

A new, extinct species of Allodia Winnertz is described from early Miocene amber of Ethiopia. Allodia paleoafricana sp. nov. is mostly characterized by the scutum with strong anteromarginal, dorsocentral, and lateral setae and the wing with the stem of the M-fork slightly shorter than the vein r–m and the base of the M4–CuA fork aligned with the base of r–m. The assignment to any of the two subgenera Allodia stricto sensu or Brachycampta Winnertz remains equivocal as the fossil intermingles traits found in both taxa. Allodia is known mostly from the Palearctic region, while only a few species have been described from Africa. In this regard, the new fossil species from Ethiopia brings significant new information regarding the Afrotropical distribution and natural history of the genus.

Rhopalosomatidae, currently considered the sister group of the Vespidae, are an enigmatic family of aculeate wasps that originated in the Late Jurassic or Early Cretaceous. Despite their considerable age, very few fossils of the family have been reported – all of them in amber (Miocene Dominican, Miocene Mexican, and mid-Cretaceous Burmese ambers). Here we report a new mid-Cretaceous rhopalosomatid wasp, Cretolixon alatum Lohrmann, gen. et sp. nov., from Burmese (Kachin) amber. This new genus has a unique mixture of characters, some of which are only known from the recent brachypterous genus Olixon and others of which are known only from the recent macropterous genera. Thus, Cretolixon Lohrmann, gen. nov. not only provides further evidence for the monophyly of the family but also contributes evidence for the monophyly of the Rhopalosomatinae. Key characters of the family are discussed, and an updated checklist of the world genera and fossil species and occurrences of Rhopalosomatidae is provided. Additionally, a chemical analysis was performed for three of the newly reported fossils as well as for the amber piece containing the rhopalosomatid larva described by Lohrmann and Engel (2017) to ascertain their amber vs. copal nature and their affinities with each other and previously described Burmese amber.

International audience; Extinct haidomyrmecine “hell ants” are among the earliest ants known [1, 2]. These eusocial Cretaceous taxa diverged from extant lineages prior to the most recent common ancestor of all living ants [3] and possessed bizarre scythe-like mouthparts along with a striking array of horn-like cephalic projections [4, 5, 6]. Despite the morphological breadth of the fifteen thousand known extant ant species, phenotypic syndromes found in the Cretaceous are without parallel and the evolutionary drivers of extinct diversity are unknown. Here, we provide a mechanistic explanation for aberrant hell ant morphology through phylogenetic reconstruction and comparative methods, as well as a newly reported specimen. We report a remarkable instance of fossilized predation that provides direct evidence for the function of dorsoventrally expanded mandibles and elaborate horns. Our findings confirm the hypothesis that hell ants captured other arthropods between mandible and horn in a manner that could only be achieved by articulating their mouthparts in an axial plane perpendicular to that of modern ants. We demonstrate that the head capsule and mandibles of haidomyrmecines are uniquely integrated as a consequence of this predatory mode and covary across species while finding no evidence of such modular integration in extant ant groups. We suggest that hell ant cephalic integration—analogous to the vertebrate skull—triggered a pathway for an ancient adaptive radiation and expansion into morphospace unoccupied by any living taxon.

Motivation for this comment Recently, the Society of Vertebrate Paleontology (SVP) has sent around a letter, dated 21st April, 2020 to more than 300 palaeontological journals, signed by the President, Vice President and a former President of the society (Rayfield et al. 2020). The signatories of this letter request significant changes to the common practices in palaeontology. With our present, multi-authored comment, we aim to argue why these suggestions will not lead to improvement of both practice and ethics of palaeontological research but, conversely, hamper its further development. Although we disagree with most contents of the SVP letter, we appreciate this initiative to discuss scientific practices and the underlying ethics. Here, we consider different aspects of the suggestions by Rayfield et al. (2020) in which we see weaknesses and dangers. It is our intent to compile views from many different fields of palaeontology, as our discipline is (and should remain) pluralistic. This contribution deals with the aspects concerning Myanmar amber. Reference is made to Haug et al. (2020a) for another comment on aspects concerning amateur palaeontologists/ citizen scientists/private collectors.

International audience; The Puy-Puy quarry at Tonnay-Charente (Charente-Maritime, SW France) is a sand quarry exposing a 9-m-thick series of latest Albian–earliest Cenomanian (mid-Cretaceous) age. The uppermost Albian deposits consist of lignitic clay containing fossiliferous amber. The lowermost Cenomanian sand deposits alternate with clay intercalations containing plant remains. One of these clay levels, named P1, shows an outstanding accumulation of conifer and angiosperm macrofossils including delicate reproductive structures such as flowers. Plant remains are associated with invertebrates such as insects (Odonata, Dictyoptera, Diptera), crustaceans (Mecochirus sp.), putative brachiopods (aff. Lingula sp.), and worms. A few vertebrate remains such as shark egg capsules (Palaeoxyris sp.) and a feather are present in the fossil assemblage, as well as an enigmatic specimen tentatively interpreted as a cephalochordate or a petromyzontiform. Various ichnofossils occur in abundance, such as crustacean coprolites and burrows (Ophiomorpha isp.), insect coprolites (Microcarpolithes hexagonalis), and leaves with grazing structures, galls and mines. The sediments have been deposited in a coastal, calm and brackish area.

International audience; The Cenomanian amber from Kachin State of Myanmar contains a diversified fauna of fossil evanioid wasps. Two new genera are described and figured, as Rasnitsevania ferox gen. et sp. nov. in the family Praeaulacidae, and Electrofoenia jehani gen. et sp. nov. in Aulacidae. Characteristic features of Rasnitsevania gen. nov. include a large mesosoma, a two-segmented metasomal petiole with first segment long, trapezoidal, and the fore wing venation with a long cell 1-mcu and a cell 2rm shorter than 3rm. Electrofoenia is characterized by the pronotum transversely striate and the fore wing with vein 1Rs less than twice as long as 2Rs, 2Rs+M short, 2M longer than 3M, and 1cu-a basal to fork of 1M and 1cu. The Praeaulacidae and Aulacidae display an extensive fossil record suggesting that the Mesozoic Evanioidea were much more diverse than today. An updated list of the fossil record of the Praeaulacidae is provided.

International audience; Ants are abundant, ecologically influential, and diverse eusocial Hymenoptera. The dominant narrative fortheir origin and radiation is that of E. O. Wilson and Bert Hölldobler, known as the “dynastic successionhypothesis”. Wilson and Hölldobler contend that the crown (= extant) ants originated during the peak of theangiosperm radiation, ~110–100 million years ago, and that post-K/Pg biodiversity recovery occurred in asequence dictated by degree of social derivation. To address this hypothesis, we reconsidered thephylogenetic scope of the problem, and generated a large morphological dataset (576 characters for 575taxa) which included extant species with ultra-conserved element (UCE) sequences and hundreds offossils. These fossils represent a comprehensive sample of Mesozoic Aculeata, Trigonaloidea,Evaniomorpha (= Evanioidea), plus the enigmatic Jurassic taxa †Bethylonymoidea and †Ephialtitoidea. Totest the geochronological prediction of the dynastic succession hypothesis, we combined the nucleotideand morphological data in a series of tip-dating analyses. To test the “scale of sociality” hypothesis, weconducted an MCMC estimation of ancestral states for all morphological characters on a distribution oftrees from our best-supported analysis, with emphasis on those traits with social-behavioral correlates.Based on the results from our two-pronged test of the Wilson- Hölldobler hypothesis, we provide areinterpretation of the origin and evolution of the ants, from the ancestor of the Aculeata to that of the crownFormicidae.

Dhagnathos autokrator sp. nov. urn:lsid:zoobank.org:act: EC8760 A 9-9 C 00-44 A 9-9311- 2EC5 DE 24 A 4 B 1. Figs. 2AeC, 3, 8 G. Etymology. The specific epithet refers to autokrator (Greek, meaning ���self-ruler���), an individual who exercises absolute power, unrestrained by superiors; in reference to the highly powerful aspect of this ant. Holotype. IGR. BU-003, alate female (Figs. 2AeC, 3EeG). Additional specimens. HA 03, XA01 and RM 1, three alate females (Figs. 3Ae3D). Horizon and locality. Upper Cretaceous, upper Albianelower Cenomanian (ca. 99 Ma); in amber from the Hukawng Valley, Kachin State, Myanmar. Diagnosis. As for the genus, by monotypy. Description (gyne). Body length ca. 14 mm. Cuticle generally smooth, without distinct sculpturing, sparsely covered by thin, long, erect setae, the head additionally densely covered by short, adpressed setae on vertex and genae. Head only slightly longer than high and wide. Vertex and posteroventral surface rounded, anterior surface relatively flat, and genae shorter than eyes and projecting anteroventrally above mandible insertion into a cheek-like lobe. Ocelli present near top of vertex, conspicuous, ocellar diameter slightly larger than width of first antennomere; interocellar distance about half of ocellar diameter. Compound eyes bulging, reniform, 2.4 as long as wide, situated posteriorly on head (EPI 440). Antennae inserted between compound eyes around their midlength, closely flanking lateral edges of clypeus; base of antenna with basal bulb exposed, inserted within thick annular torulus. Antenna geniculate, filiform; scape short, 0.5 head length, weakly arched and broadened apically; first funicular article (pedicel) very short, 0.22 scape length, less than twice as long as wide, broadened apically; flagellomeres unusually slender, funicular article II (antennomere III) about 22 as long as wide; following antennomeres gradually decreasing in length and width. Posterior clypeal margin apparently fused, while horn is the result of de novo medial margin/ridge; anterior clypeal margin broadly rounded. Clypeal horn directed upward for its basal quarter, then bent at a right angle and directed forward for remaining length; horn gently rounded apically, without expanded lobe; dorsal surface of horn convex; ventral surface emarginate, its lateral margins prominent and prolonged basally into raised frontal carinae diverging anteriorly to reach the anterior margin of head, just above insertion of mandibles. Setation of horn consisting, on ventral surface, of a dense brush of short, peg-like denticles at apex; similar peg-like denticles widely spaced and arranged in a single row on each lateral margin, and becoming progressively denser and arranged in 2e3 longitudinal rows along lateral clypeal carinae; dorsal and ventral surfaces of horn sparsely covered by thin, long, erect setae. Labrum well exposed, large, nearly trapezoid, with anterior margin convex, posterior margin slightly emarginate medially, sides unsutured to clypeus so that anterior part of labrum is apparently movable; dorsal surface of labrum rimmed laterally by a longitudinal brush of stiff, spine-like setae, also densely coated by thin, erect setae becoming progressively longer and stiffer along lateral and posterior margins. Mandibles long (MDI 97), scytheshaped, widely spaced basally and converging apically, with tips curved and acute, nearly reaching the rounded portion of the horn as preserved; basal portion linear, short; apical portion 5 as long as basal portion, curved dorsally and posteriorly, with dorsal surface concave and rimmed on each margin by row of acute teeth and thin, erect setae directed backwards; medioventral blade between basal and apical portions forming a large, isosceles, blunt tooth perpendicular to apical portion. Palps long (visible on specimen HA 03), coated dorsally in fine, tapered setae, maxillary palp with 6 segments, as long as head capsule when combined; labial palp with 5 segments. Mesosoma. Pronotal colar pronounced, concealing propleuron in dorsal view, separated from remaining pronotal dorsum by a distinct transverse ridge; pronotal dorsum strongly concave immediately anterior to ridge, nearly flat posterior to ridge; promesonotal suture deeply impressed. Mesoscutum as long as pronotum (excluding neck) in dorsal view, about as broad as long; mesoscutal dorsal outline feebly convex, with long parapsidal furrows almost reaching anterior mesonotal margin, converging posteriorly but not touching. Mesoscutellum posteriorly expanded, in dorsal view concealing median portion of metanotum; dorsal and posterior mesoscutellar surfaces concave, their junction forming a sharp angle; dorsal mesoscutellar surface with a deep, broad, transverse groove immediately posterior to scuto-scutellar suture. Metanotum medially as high as long, with posterior surface forming distinct angle with pronotal dorsum. Propodeum 1.25 as high as long, dorsal and declivitous surfaces meet at pronounced right angle, forming conspicuous ridge; dorsal surface nearly flat, declivitous surface faintly concave; propodeal spiracle slit-like, opening posteriad, at junction of propodeal dorsum and sides; metapleural gland orifice opening laterally, protected by guard setae. Legs long and robust (mostly visible on specimen HA 03); mesocoxa distinctly shorter than pro-and metacoxae; small trochantellus present on mid- and hind legs; all femora distinctly swollen in their basal half, tibiae swollen in their apical half; ventral margin of protibia apically with large calcar gently curved, protibia possessing small subapical point, and two straight, stout setae less than half as long as calcar; mesotibia apically with two long, straight, pectinate spurs, and two short, stout setae; metatibia apically with one long, pectinate spur and one long, simple spur; tarsomeres IeIV of all legs with pairs of stout setae along entire ventral surface (8e10 pairs on tI, 4e5 pairs on tII, 3 pairs on tIII, 2 pairs on tIV), and apically with 2 pairs of stout setae each flanking a spatulate spine; additionally the ventral surface of tarsomeres IeIV covered by dense brush of thin, erect setae; pretarsal claws strong, with a distinct subapical tooth. Fore wing with Rs���f2, basal portion of Rs���f3, M ���f4, and Cu1 nebulous, all other veins tubular; pterostigma elongate, ca. 6 as long as broad; a short stub of cross-vein 1r-rs present, nebulous; Rs���f1 half as long as M ���f1, both distinctly arched; Rs���f2 and Rs���f3 nearly at right angle, Rs���f2 half as long as M ���f2; 2rs-m present, situated beyond apex of pterostigma; discal and subdiscal cells pentagonal; cu-a arising from M �� Cu and proximal to M ���f1 (Cu���f1 short); vein Cu with both Cu1 and Cu2 present. Hind wing with jugal lobe present; anterior margin with 5 median and 22 distal hamuli; vein C present; vein R present, reaching distal wing margin; Rs���f1 more than twice as long as 1rs-m; cu-a arising from M �� Cu, proximal to fork of M ���f1 and Cu (Cu���f1 short); Rs���f2, M ���f2, Cu, and A ���f2 present, not reaching wing margin. Metasoma with petiole short-pedunculate, almost 0.6 as high as long; petiolar tergite a broadly convex node, with anterior surface approximately twice as long as posterior face; subpetiolar process present, in profile forming a high, transverse, lamella pointing ventrally, with anterior face concave, posterior face vertical; not fused tergosternally, suture visible; attaching broadly to gaster. Gaster elongate. First gastral tergite with helcium pronounced, forming a post-petiolar peduncle, with anterior surface behind helcium high, oblique, and dorsal surface strongly convex, short; anteriormost part of first gastral sternite with a distinct mesal process (keel) pointing anteroventrally below helcium. Second gastral segment distinctly longer than first, with presclerite largely exposed to form a deep, broad constriction between first and second gastral segments (abdominal segments III and IV). Gastral segments unfused with deep lateral suture. Following segments poorly preserved, pygidium apparently broadly acute towards sting shaft. Measurements (holotype IGR.BU-003; in mm). HL 2.50; HoL ca.1.70; EL 1.20; ocelli diameter 0.20; MDbL 0.40, MDtL 0.55, MDaL 2.00; length/width of antennomeres: I (scape) 1.15/0.16, II (pedicel) 0.26/ 0.14, III 2.16/0.10, IV 1.50/0.07, V 1.34/0.07; WL 3.85; FWL (as preserved) 6.35 (7.90 on specimen DHA 4); PL 1.84, PH 1.00, PW 0.67., Published as part of Perrichot, Vincent, Wang, Bo & Barden, Phillip, 2020, New remarkable hell ants (Formicidae: Haidomyrmecinae stat. nov.) from mid-Cretaceous amber of northern Myanmar, pp. 1-18 in Cretaceous Research 109 on pages 5-7, DOI: 10.1016/j.cretres.2020.104381, http://zenodo.org/record/3653072

Genus Protoceratomyrmex gen. nov. urn:lsid:zoobank.org:act: D219838A-DEFE-4E2C-9599- 2FFDE59970C4. Type species: Protoceratomyrmex revelatus gen. et sp. nov. Etymology. The generic name is a combination of proto - (Greek, meaning ���first���), and the most similar genus Ceratomyrmex, in reference to the very slight clypeal horn resembling an initial stage of the dramatically developed horn of other horned hell ants. The name is masculine. Diagnosis (worker). Head configuration similar to Haidomyrmex, Haidomyrmodes, Haidoterminus, Ceratomyrmex, and Linguamyrmex; head capsule tear-drop shaped, broadened posteriorly, gradually tapering anteriorly; head distinctly broad, approximately as wide as long. Mandibles scythe-like with abbreviated dorsal development and widened mandibular ���elbow��� relative to other haidomyrmecine taxa; clypeus with well-defined lateral and posterior sulci, a slight triangulate cuticular elevation present near posterior clypeal margin, flanked by elongate trigger hairs; posterolateral clypeal margins broadly rounded; frontal triangle present as a laterally flattened rectangular elevation between antennal sockets approximately equal in height to clypeal horn; eyes reduced, ocelli absent; pronotum broadened laterally; mesosoma with distinct metanotal sclerite; propodeal spiracle circular, gaping; petiole pedunculate with broadly rounded node; ventral margin of petiole unarmed; constriction present between abdominal segments III and IV with medial v-shaped projection on first gastral tergite visible dorsally., Published as part of Perrichot, Vincent, Wang, Bo & Barden, Phillip, 2020, New remarkable hell ants (Formicidae: Haidomyrmecinae stat. nov.) from mid-Cretaceous amber of northern Myanmar, pp. 1-18 in Cretaceous Research 109 on page 12, DOI: 10.1016/j.cretres.2020.104381, http://zenodo.org/record/3653072

Genus Linguamyrmex Barden & Grimaldi, 2017. Type species: Linguamyrmex vladi Barden & Grimaldi, in Barden et al., 2017: 839., Published as part of Perrichot, Vincent, Wang, Bo & Barden, Phillip, 2020, New remarkable hell ants (Formicidae: Haidomyrmecinae stat. nov.) from mid-Cretaceous amber of northern Myanmar, pp. 1-18 in Cretaceous Research 109 on page 13, DOI: 10.1016/j.cretres.2020.104381, http://zenodo.org/record/3653072, {"references":["Barden, P., Herhold, H. W., Grimaldi, D. A., 2017. A new genus of hell ants from the Cretaceous (Hymenoptera: Formicidae: Haidomyrmecini) with a novel head structure. Systematic Entomology 42, 837 e 846. https: // doi. org / 10.1111 / syen. 12253."]}

Genus Aquilomyrmex gen. nov. urn:lsid:zoobank.org:act: 5 AFEF 07 E- 2228-4A9 D-AEC 1- 8D2680267734. Type species: Aquilomyrmex huangi gen. et sp. nov. Etymology. The generic name is a combination of aquilex (Latin, meaning ���dowser���), and myrmex (Greek, meaning ���ant���), and refers to the dowsing stick-like clypeal and labral processes. The name is masculine. Diagnosis (gyne). Head dorsoventrally flattened, with large compound eyes situated dorsolaterally at anterior margin of head; with prominent, anteriorly protruding frontal shelf, clypeal horn and labrum. Antennae inserted laterally on frontal shelf, well in front of compound eyes and above base of clypeal horn; antennal scape long. Apex of clypeal horn bifurcated widely, with each bifurcation subsequently terminating in a bilobed pad; lateral margins of horn connecting obliquely with anteroventral angles of head, just above mandibular insertion, connected by a cleared vertical cuticle, rimmed by short thin erect setae and occasional serrations. Labrum situated ventrally of horn, with size and shape similar to horn except for apex, which is only bifid; ventral margin coated by peglike denticles on its basal half. Mandibles sickle-shaped, inserted ventrally very close to compound eyes, with all margins smooth (triangular blade absent) and acute tips converging between labral apex. Legs very long, with femora distinctly swollen basally, and apically with two flange-like cuticular lobes flanking the base of tibia. Petiole node-shaped, with small subpetiolar process. A deep, girdling constriction between first and second gastral segments., Published as part of Perrichot, Vincent, Wang, Bo & Barden, Phillip, 2020, New remarkable hell ants (Formicidae: Haidomyrmecinae stat. nov.) from mid-Cretaceous amber of northern Myanmar, pp. 1-18 in Cretaceous Research 109 on page 10, DOI: 10.1016/j.cretres.2020.104381, http://zenodo.org/record/3653072

Chonidris insolita sp. nov. urn:lsid:zoobank.org:act:3 A 8ED551-78 C 9e4 B 0F-8 E 10- 6 C 94641 F 5 A 08. Figs. 2DeF, 4, 8 F. Holotype. NIGP 171998, alate female (Figs. 2D, 4 H). Paratype. NIGP 172003, alate female (Figs. 2 E, 4FeG). Additional specimens. HA 04 and RM 2, two alate females (Figs. 2 F, 4AeE). Horizon and locality. Upper Cretaceous, upper Albianelower Cenomanian (ca. 99 Ma); in amber from the Hukawng Valley, Kachin State, Myanmar. Etymology. The specific epithet derives from insolitus (Latin, meaning ���strange���), and refers to the unusual accommodation of the mandibles within the clypeus. Diagnosis. As for the genus, by monotypy. Description (gyne). Body length around 10 mm. Cuticle smooth, densely covered by short adpressed setae; additionally with long, thin, erect setae sparsely covering head capsule, mesosoma, legs, and apical portions of gastral segments IeIII, setae more densely covering pygidium. Head about as long as broad, longer than high, circular in frontal view. Vertex and posteroventral surface strongly rounded, anterior surface flat, with short genae (ca. 0.2 eye length) projecting into cheek-like lobe anteroventrally above mandible insertion. Ocelli distinct, positioned on small, raised, triangular prominence; ocellar diameter as broad as base of first antennomere, interocellar distance about one ocellar diameter. Compound eyes bulging, oval, 0.6 as broad as long, removed from lateral margins of head capsule. Antennae inserted between compound eyes below their midlength, closely flanking lateral edges of clypeus at base of horn's stalk; base of antenna with basal bulb exposed, inserted within thick annular torulus opening obliquely dorsad; antenna elongate; scape ca. 0.8 head length, weakly arched, cylindrical; pedicel very short, 0.2 scape length, about as long as wide, slightly broadened apically; first flagellomere longest antennomere, about 8 as long as wide (assessed from paratype, where antennae are flattened and elongate but respective ratios are kept); following antennomeres gradually decreasing in length. Posterior and lateral margins of clypeus (epistomal sutures) visible, indicating the horn is the result of an elevated anterior margin. Clypeal horn short (HoI 28e30), expanded at right angle from frons, strongly arched with dorsal surface convex and ventral surface furrowed; lateral margins prolonged basally on frons into raised carinae diverging toward anterior angles of head, just above insertion of mandibles; ventral surface and lateral carinae rimmed by row of short, peg-like denticles, and long, fine, erect setae. Labrum exposed between clypeal carinae, with anterior margin broadly convex and slightly notched medially, posterior margin obscured; dorsal surface coated by long, thin, erect setae. Dorsal margin of mandibles curved dorsally immediately from base, in profile view without distinct elbow, their tips reaching nearby horn's apex, dorsal mandibular margin armed apically as series of sharp, curved teeth; largest apical tooth preceded by two medial teeth of equal length following slight gap; basal portion of mandible (from base to base of medioventral blade) short, simple; distal portion projected medially and ventrally in a large, triangular blade tapering to the tip; the blade with dorsal surface concave, ventral corner rounded, and apical half serrate; tip of mandible with a preapical tooth immediately following the blade and projected posteriorly, and one apical acute tooth curved posteriorly; when mandibles closed, their medial margins parallel and closely approximated, slightly overlapping at ventral corner of blade; accommodated in the triangular clypeal cavity (i.e., concealing the anterior clypeal margin, labrum and ventral surface of horn); maxillary palp with 5 visible segments, labial palp with 3 visible segments. Mesosoma about twice as long as high. Pronotal colar short, separated from remaining pronotal dorsum by a distinct transverse ridge; pronotum nearly vertical immediately anterior to ridge, feebly convex posterior to ridge (dorsum); posterior pronotal margin with distinct thickening dorsally. Promesonotal suture complete, appears flexible. Mesoscutum shorter than pronotum, mesoscutal dorsal outline faintly convex, with long parapsidal furrows converging posteriorly to reach anterior mesonotal margin. Mesoscutellum prominent; dorsal mesoscutellar surface convex, posterior surface slightly concave, their junction forming a sharp angle. Metanotum medially as high as long, with posterior surface forming distinct angle with propodeal dorsum. Propodeum 1.5 as high as long, dorsal and declivitous surfaces flat, separated by thin ridge, forming sharp angle; propodeal spiracle slit-like atop rounded nodule, situated around junction of propodeal dorsum and sides. Metapleural gland orifice a small circular concavity. Mesopleuron and metapleuron coated in thin, tapered setae. Legs robust, mesocoxa distinctly shorter than pro-and metacoxae, small trochantellus present on mid- and hind legs; all femora moderately swollen in their basal half; ventral margin of protibia apically with large calcar and two straight, stout setae less than half as long as calcar; mesotibia apically with two long, straight, spurs, one pectinate and one simple; additionally with three short stout setae; metatibia apically with one long, pectinate spur, one long, simple spur, and one short, stout seta; tarsomeres IeIV of all legs with pairs of short, stout setae along entire ventral surface (6 pairs on tI, 3 pairs on tII, 3 pairs on tIII, 2 pairs on tIV), and apically with 2 pairs of simple, stout setae each flanking a spatulate seta (�� plantar lobe); pretarsal claws strong, with a distinct subapical tooth and pulvilus. Wing venation as in Dhagnathos except, in fore wing, the pterostigma 3 as long as broad, cross-vein Rs���f1 not arched, short stub of 1r-rs tubular, M ���f2 extremely short (1m-cu almost arising at level of Rs���f2). Hind wing with 11 distal hamuli present, jugal lobe not visible, but lobe may be lost due to damage. Metasoma. Petiole short-pedunculate, massive, 0.84 as high as long; in profile, with posterior margin oblique and broadly attached to first gastral tergite (AIII); tergite and sternite of petiole and AIII unfused (suture distinct); petiolar tergite a strongly convex node, with anterior surface approximately twice as long as posterior surface which is nearly vertical in its anterior half, oblique in its posterior half; petiolar sternite with subpetiolar process and lamella (in profile) with a high, transverse tooth pointing ventrally, with anterior face flat, posterior face concave; process followed by a smaller but distinct triangular tooth. First gastral segment bellshaped; tergite with helcium faintly pronounced, with anterior surface behind helcium high, oblique, and dorsal surface strongly convex, short; anteriormost part of first gastral sternite with a distinct mesal process (keel) projecting anteroventrally below helcium. Second gastral segment (AIV) distinctly longer than first, with presclerite largely exposed to form a deep, broad constriction between AIII and AIV. Following segments more or less telescoped, pygidium convex, sting well exserted, distinctly arched dorsally. Measurements (in mm) (holotype NIGP 171998), [paratype NIGP 172003], {specimen RM 2}. HL [1.42] {1.68}; HoL [0.86] {0.658}; EL [0.72]; MDL [1.44] {1.10}; length of antennomeres: I (scape) [1.00] {0.96}, II (pedicel) [0.17] {0.21}, III [1.42] {0.92}; WL (3.66) {3.30}; FWL (5.2) {5.50}; PL (1.33), PH (excluding process) (1.12)., Published as part of Perrichot, Vincent, Wang, Bo & Barden, Phillip, 2020, New remarkable hell ants (Formicidae: Haidomyrmecinae stat. nov.) from mid-Cretaceous amber of northern Myanmar, pp. 1-18 in Cretaceous Research 109 on pages 8-10, DOI: 10.1016/j.cretres.2020.104381, http://zenodo.org/record/3653072

Linguamyrmex brevicornis sp. nov. urn:lsid:zoobank.org:act: D91488C6-3BEB-4A21-9F0E- 3101BB9CCA85. Figs. 6CeE, 7. Etymology. The specific epithet is a combination of brevi (Latin, meaning ‘short’) and cornus (Latin, meaning ‘horn’), and refers to the smaller clypeal horn compared to the type species L. vladi. Holotype. NIGP172001, worker (Figs. 6C, 7D). Additional specimens. LA01, alate female (Figs. 6D, 7AeB), and RM 4, worker (Figs. 6E, 7C). Horizon and locality. Upper Cretaceous, upper Albianelower Cenomanian (ca. 99 Ma); in amber from the Hukawng Valley, Kachin State, Myanmar. Diagnosis (females). Closely similar to L. vladi, but differs from this species by having a shorter clypeal horn (horn index HoI ¼ 31e 34 in L. brevicornis, 56 in L. vladi), with stalk much reduced, slightly broader than long, with the setose pad more hexagonal and aligned with stalk (circular and with a distinct bend between stalk and clypeal pad in L. vladi), and with clypeal pad coated in stout setae. It is also differentiated by the mandibles with two teeth on ventral corner of medioventral blade (teeth absent in L. vladi) and, in workers, with the apical mandibular portion shorter than basal portion (apical portion longer in L. vladi). In addition to the difference in the proportion of the mandible, the female castes of L. brevicornis differ by their size (body length ca. 7 mm in gyne, 4 mm in worker), by the antennae with flagellomeres compact in worker, more elongate in gyne, and by subpetiolar process present in worker. Description (gyne). Total length of body around 7 mm. Cuticle minutely shagreened, densely covered by adpressed, minute setae, the apical gastral segments additionally with sparse pilosity of long, fine, erect setae becoming gradually denser toward apex. Head. As in Linguamyrmex vladi, but with compound eyes slightly reniform, emarginate in middle of posterior margin. Ocelli distinct, positioned on a prominent cuticular triangle, in dorsal view, with posterior margin of lateral ocelli aligned with posterior margin of eyes. Antenna filiform, with flagellomeres elongate, cylindrical except apical one, which has acute tip; third antennomere twice as long as following one. Antennal sockets immediately flanking a medial frontal triangle that is sharply expanded anteriorly above clypeal horn, and connecting ventrally with dorsal surface of horn by a cleared, laterally flattened cuticle; frontal triangle projection terminates anteriorly at approximately same length as clypeal horn with slight indentation just dorsad clypeal horn, giving the appearance of a second, small, broadly rounded horn. Clypeal horn originating at base of frontal triangle, short and straight, in profile view almost perpendicular to longest axis of head. Horn paddle-shaped, with short, compact stalk and hexagonal, setose pad; stalk apparently glabrous, 0.10 mm in length, 0.12 mm in width; setose pad 0.26 mm in length, 0.20 mm at greatest diameter, with anterior margin straight, transverse; dorsal surface of setose pad glabrous, ventral surface densely and uniformly coated with very short, velcro-like vestiture; trigger hairs not visible. Lateral clypeal margins extending from above mandibular insertions toward horn as gently curved lines. Anterior clypeal margin broadly concave. Labrum visible. Mandible scythe-shaped; basal portion linear, short, meeting apical curved portion nearly at right angle; medioventral triangular blade bearing one large apical tooth and one small preapical tooth, with concave dorsal surface coated with pointed setae; apical portion of mandible posterior to medioventral blade 1.6 as long as blade, with tip broadly rounded. Mandibles preserved in closed position (with tips of apical portion reaching nearby clypeal setose pad), almost entirely parallel and closely approximated, except ventral corners of blades overlapping and tips slightly diverging. Maxillary palps 5-segmented, labial palps 3- segmented. Mesosoma. Pronotal colar pronounced but not concealing entire propleuron in dorsal view; pronotal dorsum weakly convex. Promesonotal suture present, complete. In dorsal view, mesoscutum as long as pronotum (excluding neck), about as broad as long, with lateral and posterior margins carinate; posterior mesoscutal margin broadly concave; dorsal mesoscutal surface with long parapsidal furrows almost reaching anterior mesonotal margin, converging posteriorly but not touching. In profile view, pronotal dorsal outline feebly convex, mesoscutal dorsal outline nearly flat. Mesoscutellum prominent posteriorly; posterior mesoscutellar surfaces concave, their junction forming a sharp angle; dorsal mesoscutellar surface with a deep, broad, transverse groove immediately posterior to scuto-scutellar suture. Metanotum medially as high as long, with posterior surface forming distinct angle with pronotal dorsum. Propodeum 1.3 as high as long; in profile view, propodeal dorsum distinctly lower than pronotal dorsum; propodeal dorsum nearly flat, declivitous surface feebly convex, their junction broadly rounded. Propodeal spiracle slit-like, oriented posteriad. Metapleural gland opening circular, gaping. Legs long and robust, mesocoxa distinctly shorter than pro- and metacoxae; small trochantellus present on mid- and hind legs; all femora distinctly swollen in their basal half, tibiae swollen in their apical half; ventral margin of protibia apically with large calcar and two simple, stout setae less than half as long as calcar; mesotibia apically with two long, straight, pectinate spurs, and two short, straight, stout setae; metatibia apically with one long, pectinate spur and one long, simple spur. Tarsomeres IeIV of all legs with pairs of stout setae along entire ventral surface (8e10 pairs on tarsomere I, 4e5 pairs on tarsomere II, 3 pairs on tarsomere III, 2 pairs on tarsomere IV), and apically with 2 pairs of stout setae each flanking a spatulate spine; additionally the ventral surface of tarsomeres IeIV covered by dense brush of fine, erect setae; pretarsal claws thick, with a distinct subapical tooth. Fore wing with veins M∙f4 and Cu1 nebulous, not reaching wing margin; remaining veins tubular; cross-vein 1r-rs absent; Rs∙f1 faintly arched; M∙f1 distinctly arched, twice as long as Rs∙f1; Rs∙f2 nearly at right angle with Rs þ M, half as long as M∙f2; Rs þ M and M∙f2 not aligned, so that discal cell pentagonal, with vein 1m-cu distinctly longer than M∙f1; second submarginal cell long, crossvein 2rs-m situated far beyond apex of pterostigma; cross-vein cu-a arising from Cu, shortly distal to M∙f1. Hind wing with jugal lobe present. Metasoma. Petiole short-pedunculate; petiolar tergite forming a broadly convex node, with anterior surface approximately twice as long as posterior surface; subpetiolar process present, in profile a high, transverse, tooth pointing ventrally, with anterior surface concave, posterior surface vertical; transverse sulcus visible across petiole near basal margin. First gastral segment with helcium pronounced, forming a post-petiolar peduncle, with anterior surface posterior to helcium high, oblique, and dorsal surface strongly convex, short; anteriormost part of first gastral sternite with a distinct mesal process pointing anteroventrally below helcium. Second gastral segment distinctly longer than first, with presclerite largely exposed to form a deep, broad constriction between first and second gastral segments (abdominal segments III and IV). Posterior margin of gastral segments II onward with sparse, elongate setae. Pygidium nearly glabrous while hypopygium with sparse setae; pygidium apparently broadly acute towards sting shaft. Wingless female (worker). Smaller than gyne (total length of body around 4 mm), and with the following differences: compound eyes oval, ocelli faintly visible, not positioned on a prominent cuticular triangle. Antenna more compact, with flagellomeres IIeIX gradually broadened apically, apical flagellomere with rounded apex. Clypeal setose pad more quadrangular, the ventral surface with a pair of trigger hairs originating at pad base. Mandible with medioventral triangular blade larger and apical portion (posterior to blade) reduced, 0.6 as long as blade. Mesosoma and metasoma as in L. vladi except propodeum higher than long, petiole with subpetiolar process present, and girdling constriction deeper between abdominal segments III and IV (AIII with an oblique posterior surface). Protibia with one large apical spur (calcar) and two short stout setae; mesotibia with two simple spurs and three conspicuous setae positioned along anterior margin of tibial apex; metatibia with one pectinate and one simple spur, additionally with a brush of 8e10 setae flanking the pectinate spur. Sparse, erect setae positioned on dorsum of pronotum, propodeum, petiolar tergite, and first and second gastral tergites and sternites. Pygidium not preserved. Measurements (in mm) (worker holotype NIGP 172001) [worker specimen RM 4] {gyne specimen LA01}. HL [0.82] {0.82}; EL [0.21] {0.42}; HoL [0.17] {0.36}; MDL [0.59] {0.80}; length of antennomeres: I (scape) (0.57) [0.67] {1.04}, II (pedicel) (0.09) [0.12] {0.14}, III-XII (0.35, 0.17, 0.16, 0.15, 0.15, 0.13, 0.13, 0.12, 0.13, 0.17) {0.80, 0.40, 0.34, 0.32, 0.31, 0.30, 0.30, 0.32, 0.32, 0.35}; WL [1.29] {2.29}; PL {0.70}.

Genus Chonidris gen. nov. urn:lsid:zoobank.org:act:664 B 304Ce41 C 9e4 F 39-9561- 2 B 055 E 815 C 3 B. Type species: Chonidris insolita gen. et sp. nov. Etymology. The generic name is a combination of chon�� (Greek, meaning ���funnel���) and idris (Greek, meaning ���ant���), in reference to the shape of the clypeus. The name is feminine. Diagnosis (gyne). Highly similar to Dhagnathos, but smaller (body length ca. 9 mm), with clypeus triangulate and expanded posteriorly into rounded horn, lateral margins of clypeus raised into serrated carina; propodeum with posterodorsal ridge; ventral margin of petiole with pointed spicule-like process and lamella; gastral segments I and II (abdominal segments III and IV) with conspicuous constriction. Separable from Dhagnathos with clypeal horn, apical portion of mandibles, and flagellomeres distinctly more compact; with inner margin of mandible projecting medioventrally into a large triangular blade that is gradually tapering to the tip of mandible; this blade with ventral corner rounded and dorsomedial margin serrate; in frontal view, when mandibles closed, ventral corners of blades slightly overlapping and medial margins almost parallel, nearly touching, so that labrum and clypeal area ventral to horn are entirely concealed, and mandibles are encased in clypeal triangle., Published as part of Perrichot, Vincent, Wang, Bo & Barden, Phillip, 2020, New remarkable hell ants (Formicidae: Haidomyrmecinae stat. nov.) from mid-Cretaceous amber of northern Myanmar, pp. 1-18 in Cretaceous Research 109 on page 7, DOI: 10.1016/j.cretres.2020.104381, http://zenodo.org/record/3653072

Protoceratomyrmex revelatus sp. nov. urn:lsid:zoobank.org:act: 02E35429-75CB-45F0-8446- AE4598E48E21. Figs. 6AeB, 8B. Holotype. NIGP172002, worker (Figs. 6AeB). Horizon and locality. Upper Cretaceous, upper Albianelower Cenomanian (ca. 99 Ma); in amber from the Hukawng Valley, Kachin State, Myanmar. Etymology. The specific epithet derives from revelatus (Latin, meaning ‘reveal’ or ‘show’), and refers to the clypeal margins, horn, and frontal triangle, which informed interpretations of morphological development in hell ants. Diagnosis. As for the genus by monotypy. Description (worker). Total length 4.30 mm. Cuticle generally glabrous throughout. Head. Vertex broad, gradually rounded posterolaterally, medially flattened; head capsule tapered gradually toward anterior margin with maximum width at vertex approximately 2 that at mandibular insertion; head flattened anteriorly, with steep elevational incline present dorsally to oral opening; ventral surface of head severely depressed around occipital foramen. Ocelli absent, oval-shaped eyes reduced, positioned near midlength of head in lateral view, with dorsal margin abutting vertex of head. Mandibles scythe-like, laterally flattened, dorsoventrally expanded, appearing broad in lateral view; medial margin of mandibles slightly bowed anteriorly, producing cup-like curvature; dorsally developed apical tooth arising gradually, producing curved dorsal mandibular margin from basal arm of mandible, triangulate blade present anteroventrally at “elbow” junction of basal mandibular margin and apical tooth, fine setae present on the lateral margin of this expansion; dorsal margin of mandible unarmed; length of apical tooth and basal margin of mandibles approximately equal. Maxillary palps elongate, ca 0.75 length of head capsule, comprising six equally sized palpomeres; labial palps stout, roughly equal in length to two maxillary palps, comprising four equally sized palpomeres. Clypeus elongate and steeply elevated, sclerite is well defined by sulci, posterior and lateral margins meet broadly as gradually rounded suture; small, triangulate clypeal hornpresent, slight anterior widening visible from oblique view; long, fine seta present at base of clypeal horn, approximately 2 length of horn itself, reaching beyond apex of mandibles as preserved (second, symmetrical hair flanking horn presumably lost). Antennal sockets present just dorsad posterior margin of clypeus; antenna with scape elongate, third antennomere more than twice as long as following one. Cuticle raised between antennal sockets into laterally flattened projection, likely homologous with “frontal triangle” of other haidomyrmecine taxa; projection with sharp anterior face, slightly declined dorsal face, and gradually sloping posterior face, 0.23 mm in length and 0.08 at greatest height. Mesosoma. Pronotum and propleuron anteriorly extended into neck to meet and accommodate depression of head; propleuron reduced in lateral view, only faintly visible; pronotum broadly arched and dome-like; expanded ventrally in lateral view, with maximum height approximately equal to pronotal length in dorsal view; posterior margin of pronotum demarcated by well-defined mesonotum, resulting in a sharply circular posterior margin; in lateral view, posterior margin of pronotum nearly extending to posterior margin of mesonotum. Maximum height of pronotum, mesonotum, metanotum, and propodeum all approximately equal, with metanotum and propodeum slightly lower in elevation. Propodeum height and length approximately equal, broadly rounded dorsally; large propodeal spiracle situated high, circular and gaping; metapleural gland opening slightly oval-shaped. Procoxa approximately twice as long as mid- and hind coxae; femur and tibia of each leg coated in fine setae; protibia with large calcar and two stiff setae approximately 0.33 length of calcar; mid- and hind legs with two tibial spurs of equal size; trochantellus present on mid- and hind legs; tarsomeres with fine, stiff setae on underside; conspicuous pretarsal claw present. Metasoma. Petiole longer than high, node-shaped, coated in short, fine setae; peduncle short, comprising approximately 0.2 length of petiole itself; petiole node broadly rounded, with anterior surface gradually increasing in elevation, slightly flattened dorsally; posterior surface of petiole attaches to gastral segment I (abdominal segment III) broadly, following a slight decrease in elevation; ventral margin of petiole appears unarmed, without any process or tooth. Abdominal segment III with significant helcium, approximately equal in length to petiole peduncle; sternite possessing a slight ventral keel, triangulate and projecting just ventral to petiole as preserved. Darkened lateral sulci visible on each gastral segment, present along lower one-third of the gaster. Deep constriction present as circular banding between abdominal segments III and IV, this circular constriction interrupted by slight vshaped posterior expansion of abdominal tergite III, visible from above. Pygidium with elongate, tapered setae; third valvula visible above sting; sting curved near apex. Measurements (in mm) (holotype NIGP 172002). HL 0.82; EL 0.20; HoL ca. 0.09; MDbL 0.36, MDtL 0.09, MDaL 0.41; length of antennomeres: I (scape) 0.42, II (pedicel) 0.08, IIIeXII 0.27, 0.13, 0.14, 0.12, 0.08, 0.10, 0.10, 0.11, 0.10, 0.12; WL 1.21; PL 0.33, PH 0.25.

Aquilomyrmex huangi sp. nov. urn:lsid:zoobank.org:act: 9C026315-9D66-406B-BF2E- 401F12305A2D. Figs. 2GeH, 5, 8 C. Holotype. NIGP 172000, alate female (Figs. 2 G, 5GeH). Paratype. NIGP 171999, alate female (Figs. 5eF). Additional specimens. HA 06 and RM 3, two alate females (Figs. 5AeD). Horizon and locality. Upper Cretaceous, Lower Cenomanian (ca. 99 Ma); in amber from the Hukawng Valley, Kachin State, Myanmar. Etymology. The specific epithet is a patronym honoring Mr. Huang Yiren who provided four specimens for this study. Diagnosis. As for the genus, by monotypy. Description (gyne). Estimated body length around 9 mm. Cuticle smooth, densely covered by minute, adpressed setae, the pygidium additionally with dense, fine, erect setae. Head prognathous, dorsoventrally flattened; in dorsal view, with lateral margins slightly converging posteriorly, occipital corners broadly rounded, posterior margin straight. Vertex elongate, nearly flat. Ocelli forming a small, weakly prominent triangle situated on vertex far posteriorly to posterior eye margins. Compound eyes large, oval, with outer margin only feebly extending beyond side of head laterally, situated dorsolaterally near anterior margin of head. Genae much reduced. Antennae inserted anteriorly to anterior margin of compound eyes, dorsally to base of clypeal horn, and immediately flanking lateral edges of a prominent frontal shelf; frontal shelf is distributed into a three-pronged projection comprising a median membranous support stalk, flanked by strong, turreted toruli partially concealing antennal bases in dorsal view; membranous stalk is flattened laterally, appearing as a slender line in dorsal view; in lateral view, stalk appears broad with conspicuous medial hole (potentially arising from desiccation; however, present in holotype and paratype), lower portion of stalk with ventral margin fused to the dorsal margin of the clypeal horn. Base of antenna with basal bulb exposed. Antenna geniculate, 12- segmented; scape long (SI 140), weakly arched in its basal half; pedicel short, 0.10 scape length, less than twice as long as wide, broadened apically; antennomere III and XII longest flagellomeres, AIII cylindrical, about 3.6 as long as wide, following flagellomeres gradually (weakly) increasing in width, apical flagellomere with rounded apex. Clypeal horn dorsoventrally flattened, protruding anteriorly (HoI 50), gently curved dorsally toward apex; with dorsal surface convex in profile view, ventral surface apparently concave; terminus of membranous horn bifurcated widely, with each bifurcation terminating in a subsequent bilobed pad; each pad with a small, medial, rounded lobe and a larger, lateral, rounded lobe, with tapered setae present along these lobes; lateral margins of horn connecting obliquely with anteroventral angles of head, just above mandibular insertion, by a cleared vertical cuticle, rimmed by short, thin, erect setae and occasional serrations. Labrum situated ventrally to horn, with to horn in size and shape except for apex only bifid (not each bifurcation bilobed; i.e., with the form of a snake tongue); ventral surface coated by short, darkened, thick, peg-like denticles on its basal half, additionally with sparse, long, fine, erect setae throughout. Mandibles sickle-shaped, inserted very close to compound eyes, lateral to hypostoma in ventral view; weakly spaced basally and converging apically, with tips acute and reaching to horn's apex between anterior median notch of labrum and clypeal horn; basal portion linear, directed ventrally; apical portion about 3 as long as basal portion, curved dorsally approximately at 45 from basal portion, with dorsal surface apparently concave and smooth. Palps short, not reaching to occipital margin; maxillary palp with 5 visible segments, labial palp with 3 visible segments. Mesosoma elongate, distinctly longer than high and wide. Pronotal neck pronounced, about as long as wide, 0.4 as wide as maximal width of pronotal dorsum; pronotal dorsum distinctly lower than remaining mesosomal dorsum, with posterior margin strongly concave. Promesonotal suture present, complete. Mesoscutum in dorsal view shorter than pronotum (excluding neck), shorter than broad, with a distinct oblique anterior face forming a sharp angle with pronotal dorsum. Mesoscutal dorsal outline strongly convex, with faint parapsidal furrows converging posteriorly, almost reaching posterior mesoscutal margin. Mesoscutellum anteriorly flat, posteriorly strongly convex; anterior half bordered on each side by sharp carina converging posteriorly toward posterior convexity. Metanotum medially exposed in dorsal view, about half as long as mesoscutum. Propodeum convex, about as high as long, dorsal and declivitous surfaces forming a continuous curve; propodeal spiracle slit-like, situated high on sides, opening posteriad. Metapleural gland orifice a circular concavity at posteroventral margin of propodeum. Legs very long, slender. Mesocoxa only slightly shorter than procoxa, half as long as metacoxa. Small trochantellus present on mid- and hind legs. All femora distinctly swollen in their basal half, more than twice as broad as apical portion; ventral margin of each femur apically with two flange-like cuticular lobes flanking the base of tibia, these lobes increasingly larger from fore-to hind legs. Tibiae gradually increasing in width apicad. Dorsal surface of mid- and hind tibiae with a longitudinal row of 18e20 short, erect, stiff setae, and a paired row of long, erect, fine setae. Ventral margin of protibia apically with large calcar gently curved and one stout seta less than half as long as calcar; additionally the dorsal margin with three small, stiff setae. Mesotibia apically with two small, simple spurs; dorsal margin with 4 short, stiff setae. Metatibia apically with one long, pectinate spur and one short, simple spur; dorsal margin with 2 stiff setae. Tarsomere I of all legs elongate, longer than combined length of following tarsomeres IIeV; tarsomere I of fore leg coated with longitudinal row of stiff setae on dorsal margin, and dense, short, fine, erect setae throughout; tarsomere I of hind leg very long, 0.8 as long as tibia. Pretarsal claws with a distinct subapical tooth. Fore wing with veins M∙f4 and Cu1 nebulous, not reaching wing margin; remaining veins tubular; cross-vein 1r-rs absent; Rs∙f1 faintly arched; M∙f1 distinctly arched, twice as long as Rs∙f1; Rs∙f2 nearly at right angle with Rs þ M, half as long as M∙f2; Rs þ M and M∙f2 not aligned, so that discal cell pentagonal, with vein 1m-cu distinctly longer than M∙f1; second submarginal cell long, crossvein 2rs-m situated far beyond apex of pterostigma; cross-vein cu-a arising from Cu, shortly distal to M∙f1. Hind wing with 14 distal hamuli, jugal lobe not visible, base of hind wing lost. Metasoma. Petiole short-pedunculate, twice as long as broad; petiolar tergite a broadly convex node, with anterior and posterior surfaces subequal in length; posterior surface oblique in its basal half, horizontal in its distal half; broadly attached to base of first gastral tergite; subpetiolar process reduced to a small, laterally flattened rectangle present ventrally to petiole node ascent. First gastral segment bell-shaped; first tergite with helcium pronounced, forming a post-petiolar peduncle, with anterior surface posterior to helcium high, oblique, and dorsal surface strongly convex, short. Deep, girdling constriction between first and second gastral segments (abdominal segments III and IV). Second gastral segment distinctly longer than first, with deep lateral sulcus. Dorsum and lateral margins of pygidium coated in dense, tapered setae, hypopygium with long, sparse setae at terminus. Third valvula present. Sting present, strong. Measurements (in mm) (holotype NIGP 172000), [specimen RM 3]. HL (1.40) [1.33], HW (1.05), Hh (0.50); HoL (0.86); EL (0.56 in dorsal view); MDL (ca. 1.00); length of antennomeres: I (scape) (1.47) [1.80], II (pedicel) (0.16) [0.18], III-XII (0.25, 0.18, 0.16, 0.13, 0.13, 0.16, 0.13, 0.13, 0.13, 0.25); WL [3.50]; PL (0.61).

Genus Dhagnathos gen. nov. urn:lsid:zoobank.org:act: 48DA68FC-1DF6-4 A 90-86DA- 4EF527D762 F 4. Type species: Dhagnathos autokrator sp. nov. Etymology. The generic name is a combination of Dha, a singleedged sword with long, gently curved blade common throughout mainland Asia, and often called ���the national sword of Burma���, and gnathos (Greek, meaning ���jaw���), in reference to the mandibles' shape. The name is masculine. Diagnosis (gyne). Large, robust ant, body length ca. 14 mm. Clypeus funnel-shaped resulting from extreme posterior expansion, extends well beyond antennal insertions, with lateral margins raised into carinae arising above mandible insertion and converging posteriorly to form a clypeal horn; horn bent forward at right angle from frons, its tip gently rounded, not spatulate, its underside deeply furrowed, forming a channel opening toward the labrum; clypeal carinae, including horn's edges, rimmed by stout, short, tooth-like denticles. Mandibles scythe-like, the elbow between basal and distal portions with a strong (isosceles) triangular blade pointing medially and ventrally, the apical portion long, curved upwards and backwards, acutely tapering to the tip and with dorsal (posterior) margin furrowed and serrated; mandibles widely spaced, approximated only apically, with medioventral blade not overlapping (in frontal view, when closed, with distal portions aligned with frontal carinae so that the labrum and clypeal area below horn are exposed). Labrum coated laterally by a brush of stiff, spine-like setae and long fine setae, dorsal surface sparsely covered by long fine setae, anterior margin glabrous. Antennae elongate, with flagellomeres thin and long. Ocelli and compound eyes large, the latter reniform., Published as part of Perrichot, Vincent, Wang, Bo & Barden, Phillip, 2020, New remarkable hell ants (Formicidae: Haidomyrmecinae stat. nov.) from mid-Cretaceous amber of northern Myanmar, pp. 1-18 in Cretaceous Research 109 on page 4, DOI: 10.1016/j.cretres.2020.104381, http://zenodo.org/record/3653072

International audience

International audience; Psychopsidae (silky lacewings) is a species-poor ingroup of Neuroptera. Silky lacewings show a distinct relic distribution, indicating that the group was more species-rich and diverse in the past. Silky lacewings have distinct larvae that resemble antlion larvae but differ from these in lacking teeth on their mouth parts, and in having a projecting labrum, which makes them “long-nosed antlion larvae”. These larvae are well known from Myanmar amber (about 100 mya) and Baltic amber (mostly 34-38 mya, possibly 23-48 mya), as well as from the extant fauna. We report and figure numerous additional specimens from both amber types and from ca. 100 mya old French Charentese amber, expanding the known record of well-illustrated extant and fossil specimens from 26 to 52 specimens. We compare the diversity of head shape among these larvae through time by outline analysis. Results indicate that morphological diversity was pronouncedly higher in the Cretaceous, even after sample size correction. Eocene representatives are more diverse than modern representatives, but less diverse than Cretaceous ones, in one shape aspect that explains most of the overall variation (55.7%). Eocene representatives are less diverse in another shape aspect that explains the second-most variation (26.9%), but this might reflect a lack of first larval stage specimens. There seems to be no strong correlation between size and shape. This type of analysis enables a test for the loss of diversity over time, based on morphological diversity as a proxy, without the requirement of identifying fossil larvae down to a narrow taxonomical range.

International audience; The type species of the genus Haidomyrmex Dlussky, 1996 is revised. Haidomyrmex cerberus was originally described based on a partial worker specimen only, which was later re-figured with some erroneous characters. Two worker specimens assignable to this species were recently discovered in the collection of Burmese amber from the Capital Normal University of Beijing. A revised description and comparison with the two other known species of Haidomyrmex are provided, and the diagnoses of the genus and species are emended.