Twelve specimens of early Toarcian Mecoptera and Diptera from the vicinity of Wolfsburg were investigated for the present study. The material was found during house building activities in the 1980s at the locality Große Kley in Mörse, an urban district of the city of Wolfsburg, Lower Saxony, Germany. The specimens were found in calcareous nodules of the Harpoceras falciferum Zone that occur within the Liassic black shales (Posidonia shale). Six specimens of Mecoptera, five belonging to the family Orthophlebiidae and one belonging to the Bittacidae, and six representatives of the following Diptera families were identified: Ptychopteridae, Limoniidae, Anisopodidae and the superfamily Mycetophiloidea. The fossil fauna of Wolfsburg is similar to that of other early Toarcian sites in Germany, described by Handlirsch (1906, 1939), Bode (1905, 1953) and Ansorge (1996) from Braunschweig, Dobbertin and Grimmen. Two new species are described, Mesorhyphusulrichi sp. nov. (Anisopodidae) and Archipleciomima germanica sp. nov. (Mycetophiloidea).

Here is described the oldest known species of Trichoceridae, from Sogyuty, near lake Issyk-Kul (Kyrgyzstan; Lower Jurassic: Sinemurian). The species is placed in the genus Mailotrichocera Kalugina, 1985in Kalugina & Kovalev (1985), based on isolated wings. The venation of fossil and Recent Trichoceridae is discussed in terms of the biomechanical properties of the wings. The wings of the stem lineage of the family, characterised by a short subcostal vein, also had a larger distal supporting sector than younger lineages, including Recent representatives.

Five orthopteran specimens from the uppermost Middle–lowermost Upper Jurassic of Daohugou, Inner Mongolia, China are described and attributed to the genus Sigmaboilus Fang, Zhang & Wang, 2007 (Prophalangopsidae); and a new species, S. calophlebius sp. nov., is established herein. The diagnostic characters for Sigmaboilus are revised and a key to species of Sigmaboilus, based on male forewings, is provided. Intraspecific variation in forewings of this genus is also discussed.

Abundant insect fossils have been recorded from the Lower Cretaceous of the Jiuquan Basin, but very few odonatans have been recorded. In this paper, a new damsel-dragonfly, Cretastenophlebia jiuquanensis sp. nov., is described from the Lower Cretaceous Zhonggou Formation in the Hanxiagou outcrop, Jiuquan Basin, northwestern China. This is the second species of the genus Cretastenophlebia Fleck et al., 2003. Cretastenophlebia jiuquanensis sp. nov. differs from Cretastenophlebia mongolica Fleck et al., 2003 in the presence of a broad discoidal triangle, a basally straight IR1 and less cells along the posterior wing margin between IR2 and RP2. Cretastenophlebia has been previously reported from the Lower Cretaceous of Bon-Tsagaan, central Mongolia. The new discovery expands the record of Cretastenophlebia to the Jiuquan Basin in Albian.

The Family Orthophlebiidae ranges from the Middle Triassic to the Early Cretaceous. The Wealden Mecoptera have added to our knowledge of the Mecoptera from the Early Cretaceous of southern England, but have been comparatively little studied. Here we present the description of the first orthophlebiid from the Wealden of England. Mesopanorpa brooksorum sp. nov. from England is the earliest Cretaceous representative of this genus.

One new genus and four new species of Chrysopidae are described from the Lower Cretaceous of Khasurty, Transbailakia (Russia): Mesypochrysa cannabina sp. nov.; M. naranica sp. nov.; Aberrantochrysa buryatica gen. & sp. nov.; and A. pulchella gen. & sp. nov. The abundance of Chrysopidae in Mesozoic localities is discussed.

Fossils in amber are a particularly important and unique palaeobiological resource. Amber is best known for preserving exceptionally life-like fossils, including microscopic anatomical details, but this fidelity of preservation is an end-member of a wide spectrum of preservation quality. Many amber sites only preserve cuticle or hollow moulds, and most amber sites have no fossils at all. The taphonomic processes that control this range in preservation are essentially unknown. Here, we review the relationship between amber groups and fossil preservation, based on published data, to determine whether there is a correlation between resin type and aspects of preservation quality. We found that ambers of different chemistry demonstrated statistically significant differences in the preservational quality and the propensity of a site to contain fossils. This indicates that resin chemistry does influence preservational variation; however, there is also evidence that resin chemistry alone cannot explain all the variation. To effectively assess the impact of this (and other) variables on fossilisation in amber, and therefore biases in the amber fossil record, a more comprehensive sampling of bioinclusions in amber, coupled with rigorous taphonomic experimentation, is required.

Lebanese amber contains a diverse biota from the Lower Cretaceous, and more than 150 families of arthropods have been reported as inclusions. Amongst these, caddisflies (Trichoptera) are very scarce inclusions, consisting of a few indeterminate fragments and only two inclusions that permit clear descriptions of new species. We describe the first two Trichoptera species from Lebanese amber, belonging respectively to Dipseudopsidae (Phylocentropus succinolebanensis n. sp.) and Ecnomidae (Ecnomus cretacia n. sp.). Previously, the oldest fossil representatives of both families were known from the Upper Cretaceous amber of New Jersey for Dipseudopsidae and from the Eocene Baltic amber for Ecnomidae.

Biting midges (Diptera: Ceratopogonidae) are a large family of flies that commononly appear in Lower Cretaceous to Miocene strata, with over 280 fossil species (4.3 % of the family), belonging to 49 genera (26 extant; 23 extinct). Morphological characters used in the identification of fossil genera and species are identical to those used in studies of extant Ceratopogonidae and, as a result, their potential indicative value is reliable. Two relictual extant genera, Leptoconops and Austroconops, reported from Lower Cretaceous Lebanese amber, are at least 125 million years old. Certain ceratopogonid genera are indicative for the Lower Cretaceous, Upper Cretaceous, Eocene or Miocene. A morphological character indicative for the Upper Cretaceous and Cenozoic is macrotrichia on the wing membrane of adults. Indicator species and genera are reviewed for all amber deposits. Eocene Baltic amber contains the best known fauna of biting midges, with 109 named species. Some genera are indicative of aquatic and semiaquatic habitats (predaceous genera, subfamily Ceratopogoninae), forests with rotting trees (Forcipomyia), sandy sea shore habitats (Leptoconops), a cold boreal climate (Ceratopogon) or warm climates (Nannohelea, Austroconops, Leptoconops, Meunierohelea, Metahelea). Females require a protein-rich meal and are well known for feeding on the blood of vertebrates, but many feed on other things, so this information can help with the interpretation of palaeoenvironments. Washingtonhelea taimyrica Szadziewski, 1996, described from Siberian amber, is transferred to the fossil genus Palaeobrachypogon: P.taimyricus (Szadziewski, 1996), comb. nov. For Serromyia alphea, mistakenly redescribed and illustrated from Eocene Bitterfeld amber (= Baltic amber) by Szadziewski (1993), a new name – Serromyiaerrata Szadziewski, nom. nov. – is proposed.

Helius spiralensis sp. nov., is a very peculiar species of the genus Helius (Diptera: Limoniidae), with a characteristic morphology of hypopygium not found in other representatives of this genus. This is the second Helius species described from Early Cretaceous Álava amber (Spain), and one of the oldest representatives of the genus.

Clavate (club-shaped) structures rimming mid-Cretaceous Burmese amber from Myanmar, previously misdiagnosed as fungal sporocarps, are shown to be domichnia (crypts) of martesiine bivalves (Pholadidae: Martesiinae). They are similar in form to Teredolites clavatus Leymerie, 1842 and Gastrochaenolites lapidicus Kelly & Bromley, 1984; however, the former identification is preferable, given that they are martesiine crypts in amber as opposed to a lithic substrate. Cross-cutting relationships between the clavate features and inclusions in the amber demonstrate that the features post-date hardening of the resin. The fills of the crypts are variable, including sand grade sediment of very fine to coarse sand grainsize, and sparry calcite cements. In some cases, the articulated valves of the pholadid bivalve responsible are visible inside the borings. However, one remarkable specimen contains two pairs of articulated shells ‘floating’ in amber, not associated with crypts; an observation that suggests that the resin was still liquid or soft when the bivalves were trapped in the resin. One individual is associated with an irregular sediment-filled feature and shows shell breakage. Formation of a solid rim around a liquid central volume has been documented in subaqueous bodies of resin in modern swamp forests, and argues for a close proximity between the amber-producing trees and a brackish water habitat for the bivalves. The presence of pyrite as thin films and crystal groups within Burmese amber is further consistent with such a depositional environment. Comparison of the size of pholadid body fossils with growth rates of modern equivalents allows the duration of boring activities to be estimated and suggests that small fossil pholadids in Burmese amber became trapped and died within 1–2 weeks of having settled on the resin. Larger examples present within well-formed domichnia formed in hardened resin. Since ‘hardground’ describes early lithified sediment as a substrate and ‘woodground’ describes wood as a substrate, the term ‘amberground’ is used here to described borings in an amber substrate.

A small fossil insect with scales on the wings and body was identified as a representative of Aphiesmenoptera from Burmese amber. The species is introduced here as Tarachocelis microlepidopterella (†). The insect is described in detail, and photos and line drawings are provided for wing venation, head, mouthparts, scales, legs and abdomen. All characters shared with primitive Lepidoptera and Trichoptera are symplesiomorphies or groundplan traits of Amphiesmenoptera. In addition, the Burmese fossil has a number of remarkable autapomorphies, giving it an appearance that deviates clearly from known families of Lepidoptera and Trichoptera. The species, representing a family of its own, Tarachocelidae, is considered a separate and unique taxon in the stem-group of Amphiesmenoptera and is provisionally placed as Amphiesmenoptera incertae sedis.*

*NB: See Note Added in Proof (Section 4).

We present the first specific record of a chironomid of the tribe Tanytarsini from early Eocene Cambay amber, India (52–53 Ma). The oldest known extinct tanytarsine genus, Gujaratomyia Giłka & Zakrzewska, gen. nov., is described on the basis of adult males of G. miripes Giłka & Zakrzewska, sp. nov. The species displays an unusual leg structure with unique leg ratios and tibial armature. The combination of the head and genital apparatus characters supports the hypothesis that Gujaratomyia and Cladotanytarsus are members of a common group within the subtribe Tanytarsina.

The first representative of Tipulomorpha in Early Eocene Cambay amber from India is described. The new find belongs to the genus Dicranomyia in the family Limoniidae. This genus has a worldwide distribution today and is relatively common in Eocene Baltic amber. A new species belonging to the subgenus Dicranomyia is described as Dicranomyia (Dicranomyia) indica sp. nov.

A new species of the genus Dicranomyia Stephens, 1829 (Diptera: Limoniidae) from Baltic amber is characterised, illustrated and described. This finding represents the second fossil of the subgenus Melanolimonia. The morphological features of the new species and the morphology comparison with its closest fossil relatives are discussed.

The family Achilidae (Hemiptera, Fulgoromorpha, commonly called planthoppers) is one of the least known and least understood groups, due to their cryptic lifestyle. They appear in the fossil record in the Lower Cretaceous, with a single genus and two species from the Crato Formation of Brazil. The oldest amber inclusion is reported from the earliest Late Cretaceous amber of Burma. Surprisingly, Achilidae are relatively common among the larger inclusions that can be found in Eocene Baltic amber. The first description of a fossil species was in the mid-19th Century. Currently, there are 13 genera and 16 species known from fossils, of which nine genera and 11 species are from Baltic amber. However, many of them need reconsideration, revisionary studies and placement in the phylogenetic context of the family. Former studies on inclusions in this amber revealed several unique forms (extinct tribes Ptychoptilini and Waghildini), or taxa ascribable to the sparse Recent tribe Achilini. This paper provides an overview of the knowledge of fossil Achilidae, particularly those from Baltic amber. The Eocene appears to be the heyday of the family; however, this hypothesis should be tested with further detailed studies.

Based on two well-preserved specimens from late Eocene Baltic amber, a new fossil species belonging to the family Trogossitidae, Seidlitzella hoffeinsorum sp. nov., is described. This is the second known fossil species of the tribe Gymnochilini and the second known species of the genus Seidlitzella. The systematic and biogeographical relations of the genus to other members of the Gymnochilini are discussed. It is hypothesised that the extant eastern Mediterranean species Seidlitzella procera may be phylogenetically related to the genus Phanodesta, today distributed in New Zealand, New Caledonia, Lord Howe Island, Juan Fernandez Island and Sulawesi.

At least since the Cretaceous Terrestrial Revolution, the geographical distribution of aphids, particularly in the Northern Hemisphere, has been strongly affected by the low thermal tolerance of their obligatory bacterial symbiont, Buchnera aphidicola, which was why the aphids switched to obligate parthenogenesis in low latitudes. Hormaphidids and greenideids penetrated into the tropics only after the Oligocene strengthening of climate seasonality, and specialisations of the tropical representatives of these families did not allow them to spread further south (in the case of cerataphidines), or only allowed in few cases (in the case of greenideids).

Aphids suffered from the Mesozoic–Cenozoic boundary extinction event much more strongly than other insects. The extinction was roughly coincidental with the establishment of the tight symbiosis of aphids with formicine and dolichoderine ants, which was accompanied by the flourishing of all three groups.

In the Cretaceous, all of the representatives of extant and subfamilies occupied positions that were subordinate to Armaniinae and Sphecomyrminae. Prior to large ant colonies evolving their efficient ant–aphid mutualism, the aphids remained unprotected before the growing ant predation. The origin of the aphid trophobiosis with large colonies of Formicinae and Dolichoderinae has resulted in the steep decline of aphids left beyond that ant–aphid symbiotic network. By at least the basal Eocene (unlike the Late Cretaceous), ant proportions in the entomofauna increased sharply, and evident dominants emerged. Even now, aphid milkers from small colonies (hundreds of specimens) never protect their symbionts, and homopteran-tending ants are more likely to be dominant, with large colonies of 104–105 workers.

The mutualistic ant–aphid system failed to cross the tropical belt during the Cenozoic because of Buchnera's low heat tolerance. As a result, the native southern temperate aphid fauna consists now of seven genera only, five of which are Late Cretaceous relicts. Some of them had relatives in Late Cretaceous amber of the Northern Hemisphere.

A diversity of filamentous microfungi was discovered from thallus surfaces of epiphytic lichens preserved in Bitterfeld and Baltic amber. We report seven distinct morphologies of dematiaceous hyphomycetes, some of which closely resemble species of the extant genera Sporidesmium, Taeniolella s. lat. and Taeniolina. Both the placement of the fungi on their substrates and the exquisite preservation of delicate structures indicate that the fungi were fully developed before they were engulfed by fresh resin. The lichens probably grew on the trunks of resin producing trees and became embedded in resin flows together with their fungal associates. The findings demonstrate that a wide range of presumably specialised fungi have lived on living and decomposing lichen thalli at least since the Paleogene. The findings add an interesting new component to the as yet poorly known mycota of the ancient European amber forests.

Fossil tree resins preserve a wide range of animals, plants, fungi and microorganisms in microscopic fidelity. Fossil organisms preserved in an individual piece of amber lived at the same time in Earth history and mostly even in the same habitat, but they were not necessarily parts of the same interacting community. Here, we report on an in situ preserved corticolous community from a piece of Miocene Dominican amber which is composed of a lichen, a moss and three species of leafy liverworts. The lichen is assigned to the extant genus Phyllopsora (Ramalinaceae, Lecanoromycetes) and is described as P.magna Kaasalainen, Rikkinen & A. R. Schmidt sp. nov. The moss, Aptychellites fossilis Schäf.-Verw., Hedenäs, Ignatov & Heinrichs gen. & sp. nov., closely resembles the extant genus Aptychella of the family Pylaisiadelphaceae. The three leafy liverworts comprise the extinct Lejeuneaceae species Cheilolejeunea antiqua (Grolle) Ye & Zhu, 2010 and Lejeunea miocenica Heinrichs, Schäf.-Verw., M. A. M. Renner & G. E. Lee sp. nov. and the extinct Radulaceae species Radula intecta M. A. M. Renner, Schäf.-Verw. & Heinrichs sp. nov. The presence of five associated extinct cryptogam species, four of which belong to extant genera, further substantiates the notion of a stasis in morphotype diversity, but a certain turnover of species, in the Caribbean since the early Miocene.