Abstract The extinct Eocene fly genus Kelneria Matile, 1979 is characterized by extreme modification of male genitalia within the family Keroplatidae. However, their morphology has remained poorly understood, as fossil material cannot be examined using traditional entomological techniques. To overcome this limitation, we applied micro-computed tomography (µCT) and synchrotron radiation micro-computed tomography (SRµCT) to reconstruct the genitalia through segmentation of scan data, enabling reassessment of the spatial organization and homology of their structures. Our analyses indicate that Kelneria was both morphologically distinctive and well represented in Eocene amber assemblages. They also support the synonymization of the Oise amber genus Eokelneria Hebert, Ngô-Muller & Nel, 2025 with Kelneria Matile, 1979, demonstrating that the characters used to establish Eokelneria fall within the range of variation observed in Kelneria. We further demonstrate that the species-level diversity of Kelneria has been underestimated and describe three new species: Kelneria rovnensis Pełczyńska & Perkovsky sp. nov., K. erroris Pełczyńska, Krzemiński & Soszyńska sp. nov. and K. szymoni Pełczyńska, Krzemiński & Soszyńska sp. nov. Additionally, identification of representatives in Rovno and Oise ambers extends the geographic and temporal range of the genus to the early Eocene (c. 53 Ma). Taken together, these findings show that Kelneria was an abundant, diverse, and widespread genus in the Eocene but has no modern representatives. The reasons for this extinction remain unknown; however, contrasting distribution of Eocene and extant representatives of the tribe Robsonomyiini suggests that this disappearance may reflect a broader faunal turnover in Europe after the Eocene.

Heiemantispa storozhenkoi gen. et sp. nov. (Neuroptera: Mantispidae) is described from the earliest Eocene Fur Formation, Denmark. The genus is distinguished from others of the family by a combination of forewing character states: a simple CuP (unique in Drepanicinae, if it belongs to that subfamily) and a basally unfused M and R. The venation of Heiemantispa gen. nov. is most similar to that of Protheristria Makarkin et al., 2025, also from the Fur Formation. Both genera are known only from incomplete wings of their type species, the venation of which does not allow them to be confidently assigned to either the subfamily Drepanicinae or Calomantispinae.

Rovnopholcomma wunderlichi gen. et sp. nov. is described from Eocene Rovno amber (Ukraine). The new genus is the closest relative of Succinura Wunderlich, 2008, known from the Eocene Baltic (Gda & nacute;sk Bay), Danish and Bitterfeld ambers. The controversial theridiid subfamily Pholcommatinae Simon, 1894 is here delimited and divided into two tribes: 1) Pholcommatini Simon, 1894, which includes the extant genus Pholcomma Thorell, 1869 and eight extinct genera, all known from the Eocene of Europe; and 2) Theonoini Simon, 1894, which includes the extant genera Theonoe Simon, 1881, Carniella Thaler & Steinberger, 1988 and Robertus O. Pickard-Cambridge, 1879. One of the key diagnostic characters for the newly delimited Pholcommatinae is the presence of hooded trichobothrial bases, a unique feature within the family Theridiidae.

The first representative of the long-jointed beetle genus Sora Walker, 1859 (Lagriinae: Lagriini Latreille, 1825) from Eocene is described and illustrated. The taxon represents the first Tenebrionidae Latreille, 1802 known from Danish amber.

Roproniidae are treated here as a small family of approximately 25 extant species in four genera, apparently closely related to Proctorenyxidae. Clarifying the phylogenetic position of these two lineages within Proctotrupoidea remains a difficult and pressing task requiring broad, integrative analyses. The family is most diverse in eastern Asia, continental China (Shaanxi, Hunan, Fujian, Zhejiang, Guizhou, Sichuan, and one species near the Kachin border), Taiwan, Japan (Honshu, Hokkaido), Kunashir and southern Sakhalin (Townes, 1948; Yasumatsu, 1956, 1958; Lin, 1987; He & Chen, 1991; Yang, 1997; He & Xu, 2015). Three Nearctic species occur in the USA (both coasts) and southern Ontario (Townes, 1948; Porter, 2002). In the Western Palaearctic, two species are known from southern Turkey (Hatay and Karatepe; Madl, 2001). The first European fossil was described from the Paleocene of Menat, France (Garrouste et al., 2016). Named earlier fossil representatives of Roproniidae are otherwise limited to the Cretaceous Kachin amber (Engel & Huang, 2017) and four genera with five species in the extinct subfamily Beipiaosiricinae Hong, 1983 (Middle Jurassic–Early Cretaceous of China and Eastern Siberia) (Rasnitsyn, 1990; Zhang & Zhang, 2001). The present study adds a new roproniid from the Ypresian Fur Formation of the Limfjord region (Northern Jutland, Denmark), constituting the second Cenozoic and youngest European fossil representative of the family.

Megalomus densistriatus Henriksen, 1922 (Neuroptera: Hemerobiidae) from the earliest Eocene Fur Formation (Denmark) is redescribed based on the holotype and 57 additional forewings. The assignation of the species to the Eocene genus Archibaldia Makarkin, 2023 is confirmed, as A. densistriata; it possesses all diagnostic character states of this genus. This species is one of most abundant Neuroptera in this formation occurring mainly in positive ash layers (younger) of the lower horizons of the Silstrup Member, but two specimens are found in the negative layers (older) of the lower to upper horizons of the Knudeklint Member. Archibaldia densistriata likely preferred upper microthermal to lower mesothermal mesic climate conditions similar to those estimated for A. wehri (Makarkin et al., 2003) from the early Eocene of western North America.

Bristly millipedes face many challenges regarding fossilisation (i.e., soft body, hidden living environments) and are clearly under-represented in the literature. Surprisingly, they are quite common in amber, offering an exceptional window to investigate their evolutionary history of the past 100 million years. Hundreds of inclusions in amber that cover the almost complete ontogenetic sequence of both Polyxenidae and Synxenidae have been investigated, and for each specimen distances between ten landmarks are measured. In contradiction to previous expectations, representatives of both Polyxenidae and Synxenidae have significantly changed through time, going from “dwarfs” during the Cretaceous ( 100 Ma) to “giants” during the Eocene ( 35 Ma); extant representatives are found in-between. This first attempt in investigating morphological changes in bristly millipedes may suggest the potential influence of the environment on the evolutionary trajectories within this group. The Cretaceous was a time of warmer climates, with tropical rainforests on the Burma Terrane, while the Eocene and modern-day representatives are from equable and temperate regions. Potentially, the environmental conditions on the Burma Terrane pressured bristly millipedes to reach “dwarf” sizes. The observed signals may be an indication of the Temperature-Size Rule, favouring quick development while slow growth in warmer ecosystems.

We describe one genus and species and undetermined immature female instar of scale insects from Sakhalinian amber found in 1972 on the Okhotsk Sea’s (South Sakhalin) beaches. Podococcus elzbietae Kalandyk-Kołodziejczyk & Wegierek gen. et sp. nov. belongs to the family Eriococcidae and it is the first known fossil adult female of this family. Other fossil species of Eriococcidae were described on the basis of immature instars or adult male. Podococcus elzbietae is characterized by the presence of 8-segmented antennae, tarsal digitules knobbed significantly longer than claw digitules, claw digitules knobbed, macrotubular ducts scattered on the margins of venter of abdominal segments, enlarged conical setae on entire body margin, anal lobes prominent with 3 enlarged setae and anal ring with 4 pairs of setae. The other specimen was not assigned to the species, but its morphological features indicate that is the first known fossil immature instar of the family Pseudococcidae. The other fossil species of this family were described on the basis of adult male morphology. The immature female instar of the family Pseudococcidae possess 6-segmented antennae with the longest apical setae, legs well developed, tarsal digitules knobbed longer than claw digitules, claw with denticle, anal lobes protruded with long apical setae, anal ring with 3 pairs of setae, tubular ducts on dorsal abdominal margins. Scale insects have not been described from the Sakhalinian amber to date.

The soldier beetle genus Malthinus Latreille, 1805, belonging to the tribe Malthinini (Malthininae), is widely distributed in the Holarctic, also penetrating into the Neotropics and the Oriental Region. Being one of the most species-rich in the family, it comprises over 350 species, the greater part of which, about 300 species, occur in the Palaearctic (Delkeskamp, 1977; Kazantsev & Brancucci, 2007).

Pedioura rotunda gen. et sp. nov., a fossil leafhopper from Eocene Baltic amber, is described, illustrated and placed in the extinct tribe Protodikraneurini. A key for identification of the seven known genera of the tribe is provided. Some morphological traits of the new fossil, including the very short inner apical cell of the forewing and footlike style apex, appear to be transitional between Protodikraneurini and the modern typhlocybine tribe Typhlocybini, suggesting that Protodikraneurini gave rise to both Dikraneurini and Typhlocybini.

Three new specimens of the widely distributed Mesozoic genus Mesypochrysa Martynov, 1927 (Neuroptera: Chrysopidae: Limaiinae) are reported from the lowermost Eocene Fur Formation, Denmark: two of M. nielseni Makarkin and Perkovsky, 2023, and one of M. frandseni n. sp. While the venation of their forewings is typical of the genus, their hind wing venation differs significantly from older congeners by two characters: MA and MP are fused distally for a short distance, and MA and the basal branches of RP are strongly zigzagged, characteristic of younger Chrysopinae. Drakochrysa Yang and Hong, 1990 is regarded as a junior synonym of Mesypochrysa, syn. nov., and accordingly Drakochrysa sinica Yang and Hong, 1990 as Mesypochrysa sinica (Yang and Hong, 1990), comb. nov. The preoccupied name of Mesypochrysa sinica Khramov et al., 2016 is replaced by the new name M. khramovi, nom. nov. Protochrysa brevin (c) 2025 Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

The Eocene taxa of fire-coloured or cardinal beetles, Pyrochroidae Latreille, 1806 are discussed with regard to the likely dark colouration of adults. Serratopogonocerus succinius gen. et sp. nov. from Eocene Baltic amber is described and illustrated. Its taxonomic position is discussed and supplementary description and images are provided for another Eocene Baltic amber species currently attributed to Pyrochroidae, Palaeopyrochroa crowsoni M. Abdullah, 1965. A brief overview of extinct Pyrochroidae reported from Eocene ambers of Europe is provided and a short discussion on their colour pattern is provided.

A new hairy fungus beetle, Danophaea cimbrica gen. et sp. nov. from the tribe Mycetophagini (Mycetophaginae), is described from late Eocene Danish amber. The new genus differs from the genus Typhaea Stephens, 1829 in that it has a short, triangular mesepimeron and mesoventrite, shorter precoxal portion of the prosternum, bent posteriorly posterior edge of mesoventrite, and elongated ninth and tenth antennomeres. It also differs from the genus Aggerbille Legalov et Perkovsky, 2024, in that its body is covered by shorter setae, and its antennal club is wider. Furthermore, the shortest distance between the mesocoxal and metacoxal cavities is distinctly greater than the length of the first abdominal ventrite at the same point. It can also be distinguished from the genus Olmia Legalov et Perkovsky, 2025 by the fact that its antennae are shorter, extending beyond the middle of the pronotum; its eleventh antennomere is distinctly shorter than ninth and tenth antennomeres combined; and its body is two times larger. This is the first record of Crowsonium succinium Abdullah, 1964 in Danish amber.

Danomantispa frandseni gen. et sp. nov. (Neuroptera: Mantispidae: Drepanicinae) is described from the earliest Eocene Fur Formation, Denmark. This is the first record of Mantispidae from this formation, and the northernmost finding of Drepanicinae. The new genus is easily distinguished from other drepanicine genera by mantispine-like pterostigma: the distal crossvein between Sc and RA is located in the distal part of the pterostigma, and the section of Sc distad it is nearly straight and rather short. Both Cenozoic genera (this genus and Vectispa Lambkin, 1986) are to some degree intermediate between Drepanicinae and Mantispinae: Danomantispa gen. nov. is a drepanicine with a mantispine-like pterostigma, and Vectispa is most probably a mantispine with a drepanicine-like pterostigma. Data on the climatic conditions of the existence of the subfamily in the past and today are summarized. We assume that the Fur Formation climate at the time of D. frandseni sp. nov. was highest microthermal/low mesothermal.

A new genus, Olmia gen. nov. with type species Olmia drevlyanica sp. nov. from the tribe Mycetophagini (Mycetophaginae), is described from late Eocene Rovno amber. The new genus differs from the genus Neotriphyllus Lawrence et al., 2014 by widely separated mesocoxal cavities, very long last antennomere and small unicolorous body. This is the first named Mycetophagidae from late Eocene Rovno amber.

A new genus, Anomalocys gen. nov. with type species Anomalocys lawrencei sp. nov., is described and illustrated from late Eocene Danish amber. The new genus differs from all other genera of the family Ciidae by its seven-segmented antennae with a compact club consists of three fused antennomeres. This is the first extinct genus of the family Ciidae.

Waninka haikowielandi Simutnik gen. et sp. nov. is described and illustrated based on a female specimen from amber found in Lower Lusatia (Germany). This parasitic wasp is the first known record of a hymenopteran discovered in amber from Lower Lusatia and is believed to be from the late Eocene. The new genus is characterized by very long postmarginal and stigmal veins, the first funicular segment ring-like and conspicuously smaller than the second one, and the eye not reaching the occipital margin. The taxonomic position of the new genus is incertae sedis within the subfamily Encyrtinae. An updated key to the genera of late Eocene encyrtids of the subfamily Encyrtinae is provided. The “Baltic river” as the route of amber redeposition to Lower Lusatia is discussed.

Encyrtidae is a large family of parasitic wasps, containing some 5,100 described extant species (Noyes, 2023). Five monotypic genera of the earliest fossil Encyrtidae are known from middle Eocene Sakhalinian amber (~45 Ма) (Simutnik, 2014, 2020; Simutnik et al., 2021). Some 20 species in 18 extinct genera of Encyrtidae have been described from late Eocene (~35 Ma) Baltic, Danish, and Rovno ambers (summarized in Simutnik et al., 2023). Several undescribed encyrtids were reported by Noyes & Hayat (1994) and Manukyan (1999) from Baltic amber. One more monotypic genus was described from amber found in Lower Lusatia (Germany), which is probably also dated to the late Eocene (Simutnik et al., 2025). In addition, one species is known from a late Oligocene (23–24 Ma) compression fossil from Rott, Germany (Statz, 1938), and two more species from two extant genera are described from early-middle Miocene (15–20 Ma) Dominican amber (Zuparko & Trjapitzin, 2014; Poinar, 2020).

The extinct genus Aetheapnomyia Harbach & Greenwalt, 2012 (Diptera: Culicidae) and its type species, At. hoffeinsorum (Szadziewski, 1998), originally described from Baltic amber, are more fully described based on a specimen of the type species recently found in Rovno amber. Dipteran inclusions in Baltic and Rovno ambers are reviewed and the possible affinities of Aetheapnomyia with extant aedine mosquitoes are explored.

The family Hybotidae (Insecta: Diptera, Empidoidea) is recorded for the first time from the bio-inclusions of Sakhalinian amber (Russia). Almost all inclusions studied belong to the subfamily Tachydromiinae. First results suggest that tachydromiines were not uncommon in a palaeo-biotope, where a resin known nowadays as Sakhalinian amber was produced. A new genus and species, Eoplatypalpus sachalinensis gen. et sp. nov., are described and illustrated. In addition, the inclusions of two tachydromiine species of unclear genera (or genus) have been examined but not named. Preliminarily, the palaeo-fauna of Tachydromiinae of Sakhalinian amber is characterised by the presence of only primitive representatives. They show an affinity with the most primitive extant genera of the subfamily (such as Symballophthalmus Becker and Megagrapha Melander) and with the group of extinct genera known from Upper Cretaceous inclusions (Cretoplatypalpus group of genera). The paleontological records of Tachydromiinae are briefly discussed. In addition, it is shown that Symballophthalmus clavilabrosus Hong described from Ypresian Fushun amber of China actually belongs to a different, as of yet uncertain genus. Consequently, fossils of the primitive extant genus Symballophthalmus remain unknown. An identification key to fossil genera of Tachydromiinae (exclusive of Drapetidini) is provided.