Fossil Insects Research Articles

Soft tissue histology of insect larvae decayed in laboratory experiments using microbial mats: Taphonomic comparison with Cretaceous fossil insects from the exceptionally preserved biota of Araripe, Brazil

Experimental taphonomy using microbial mats offers new insights into the mechanisms involved in the decay of organisms and their preservation as fossils. In this paper, the experimental decay products of soft-bodied insect larvae (the greater wax moth, Galleria mellonella, and the mealworm, Tenebrio molitor) in microbial mats have been described and compared with those of grylloid fossils derived from the Cretaceous Crato Formation of Brazil. This novel approach characterises the decay and mineralisation of different tissues (cuticle, gut tract, silk gland, trachea, and fat body tissues) using transverse histological sections. Multivariate seriation statistics using histology indicate a significant non-random process, in which the two species show the same general decay sequence, namely: decay of fat bodies and muscles on Day 11, digestive degradation and occurrence of endogenous bacteria on approximately Day 30, and degradation of cuticles and tracheal networks (the most perdurable) on Days 60 and 120, respectively. Principal component analysis, based on the qualitative features of the decaying state of tissues, showed that the greatest alterations occurred between Days 60 and 180 in the controls without mats; however, in the microbial mat experiments, larvae showed better preservation overall. Based on scanning electron microscopy and energy-dispersive X-ray spectroscopy, mineralisation of the larvae extends outside the cuticle and inner tissues. The predominance of certain anions (sulfate, chloride, and phosphate) is associated with the microbial activity of the mat community and the composition of water. The organic mesh of exopolymeric substances and cyanobacteria enriched in elements (e.g., Na and Mg) formed an amorphous crust that covered the larval body. This crust is similar to the massive crystallised external film found on the grylloid fossils derived from the Crato Formation of Brazil. The minerals were found to vary with location and time, with sulfates appearing mostly internally and for longer periods. Sulfurisation is discussed as the principal preservation process and is rapid in the early stages of organic matter decay. This comparison between the outcomes produced by taphonomic experiments using actual microbial mats and exceptionally preserved fossils can provide valuable information to understand more about the formation of numerous Konservat-Lagerstätten.

Menatanthus mosbruggeri gen. nov. et sp. nov. \u2013 A flower with in situ pollen tetrads from the Paleocene maar lake of Menat (Puy-de-D\xf4me, France)

The Paleocene Fossil-Lagerstätte Menat in France is well known for its wealth of outstandingly well preserved fossil insects and plants. Despite being known for more than a century, the palaeoflora, which is regarded as typical for the late Thanetian by some authors, has largely been neglected since the 1940s. New excavations and surveys yielded exceptionally well-preserved plant material, including a minute, heptamerous flower bearing in situ pollen tetrads, comparable to tetrads of the modern ericacean genus Kalmia L, in its anthers. The only known modern ericacean genus which is characterised by heptamerous flowers is Bejaria Mutis ex L., a basal relative of the tribe Phyllodoceae within Ericaceae, which also includes the genus Kalmia in a relatively basal position. However, heptamerous flowers also occur very rarely (mostly interpreted as teratologies) in a number of other modern Ericaceae, but also in various other modern angiosperm families. Due to the unique combination of a heptamerous flower with Kalmia-type pollen tetrads within the anthers, the new taxon Menatanthus mosbruggeri gen. nov. et sp. nov. is erected. The lack of morphological data from the flower itself and the fact that comparable pollen tetrads can be produced by a number of modern families, however, prevent an assignment of the new taxon to any known angiosperm family.

<p><strong>Two new Mesozoic species of Tipulomorpha (Diptera) from the Teete locality, Russia </strong></p>

In Siberia, there are numerous Jurassic and Cretaceous locations abundant in fossil insects. The Teete outcrop (renamed Kempendyay) located in the eastern Siberia (Russia) is an important site due to its age estimated to beginning of the Lower Cretaceous as well as its high taxa diversity and very good specimen preservation. However, it is poor in fossils of the Limoniidae. Study of the rare Tipulomorpha material from the Teete locality (= Kempendyay) is presented herein and two new species are described and illustrated. One of them belongs to the family Pediciidae, Prearchitipula ryszardi sp. nov., and the second to the family Limoniidae, Eotipula wieslawi sp. nov. Both species are dedicated to two well-known Polish specialists of fossil Diptera Nematocera.

Jomon pottery and maize weevils, Sitophilus zeamais, in Japan

Recent research in Japan using the ‘impression method’ has revealed Jomon vessels containing a large number of plant seed impressions in the clay, including from soybean and adzuki bean seeds. Additional research has been published about a vessel with a large number of maize weevils (Sitophilus zeamais). Although there were differences in the seeds and insects found in the clay, it is thought they resulted from intentional mixing with the hope of increasing cultivated plant fertility. This could mean that the cultivated plants had a significant meaning as a staple food and as spiritual objects during the Jomon period. These cultural practices indirectly prove that the Jomon people were not just hunter-gatherers, but also hunter-cultivators. However, there is strong opposition to this intentional mixing theory and the existence of plant cultivation during the Jomon period. Due to the small number of recoveries of pottery with a large number of seeds and insects from the Jomon sites, researchers have counter-argued that the introduction of these seeds and insects into the clay was coincidental. In response, it has been suggested that few discoveries have been made due to fragmentation of the pottery into small sherds, which makes it difficult to observe seeds and insects or to search for unexposed cavities in the pottery fabric. To solve this problem, X-ray equipment can be used to detect not only seed and insect impressions on the pottery surface, but also the unexposed cavities in the pottery fabric. The mechanism for introducing the seeds and insects into the pottery was clarified through the weevil-rich pottery discovered by the authors at the Late Jomon site in Miyazaki prefecture. The weevils seem to be consciously incorporated into pottery clay along with other plant residues, especially acorn shells. However, it is not known whether the potter put the weevil into the pottery while praying about the abundant fertility of the acorn. Still, this potsherd can be seen as evidence that the weevil at that time was closely related to the storage of acorns. With the exception of these Jomon period cases, there are almost no excavated Sitophilus spp. beetles in East Asia, and their formation process as a modern rice pest is still unclear. To solve these problems, we recommend searching for insect fossils in pottery as in this study.

DNA from resin-embedded organisms: Past, present and future.

Past claims have been made for fossil DNA recovery from various organisms (bacteria, plants, insects and mammals, including humans) dating back in time from thousands to several million years BP. However, many of these recoveries, especially those described from million-year-old amber (fossil resin), have faced criticism as being the result of modern environmental contamination and for lack of reproducibility. Using modern genomic techniques, DNA can be obtained with confidence from a variety of substrates (e.g. bones, teeth, gum, museum specimens and fossil insects) of different ages, albeit always less than one million years BP, and results can also be obtained from much older materials using palaeoproteomics. Nevertheless, new attempts to determine if ancient DNA (aDNA) is present in insects preserved in 40 000-year old sub-fossilised resin, the precursor of amber, have been unsuccessful or not well documented. Resin-embedded specimens are therefore regarded as unsuitable for genetic studies. However, we demonstrate here, for the first time, that although a labile molecule, DNA is still present in platypodine beetles (Coleoptera: Curculionidae) embedded in six-year-old and two-year-old resin pieces from Hymenaea verrucosa (Angiospermae: Fabaceae) collected in Madagascar. We describe an optimised method which meets all the requirements and precautions for aDNA experiments for our purpose: to explore the DNA preservation limits in resin. Our objective is far from starting an uncontrolled search for aDNA in amber as it was in the past, but to start resolving basic aspects from the DNA preservation in resin and search from the most modern samples to the ancient ones, step by step. We conclude that it is therefore possible to study genomics from resin-embedded organisms, although the time limits remain to be determined.

Behaviors and Interactions of Insects in Mid-Mesozoic Ecosystems of Northeastern China

During the past 20 years, more than 1,600 species of well-preserved fossil insects, including members of over 270 families within 24 orders, have been described from the Middle Jurassic Yanliao Entomofauna and Early Cretaceous Jehol Entomofauna in Northeastern China. Diversified fossil insects not only document the origin, systematics, and early evolution of many lineages, but also reveal these lineages' behaviors and interactions with coexisting plants, vertebrates, and other insects in their ecosystems. Fossil evidence has been documented, for example, regarding insects' feeding and pollination mutualism with gymnosperms; ectoparasitic feeding on blood of vertebrates; camouflage, mimicry of gymnosperm plants, and eyespot warning; sound stridulation for attracting potential mates; and sexual display, mating, egg-laying, and parental care. In this article, we review the diverse taxonomy of mid-Mesozoic insects of Northeastern China and elucidate their behaviors and interactions within their ecosystems, which have impacted their early evolution and development into extant insects.

Earliest record of fossil insect oothecae confirms the presence of crown‐dictyopteran taxa in the Late Triassic

AbstractAlthough dissimilar in their overall appearance and life habits, the praying mantises (Mantodea) and cockroaches (Blattodea, including their eusocial relatives, the termites [Isoptera]) are grouped within the clade Dictyoptera, based on – among other significant characteristics – the laying of eggs in a compound structure called an ootheca. The origin of the Dictyoptera and the currently recognized taxa within is, however, a controversial topic among entomologists. This has resulted from disparities in the divergence age estimates obtained from phylogenetic analyses based on molecular data together with the limited and controversial fossil evidence attributable to these groups. Here, we report two new oothecae ichnospecies found in a Carnian (237 to 227 mya. lowermost Upper Triassic) deposit from Argentina. Morphological comparisons and Scanning Electron Microscope and X‐ray Energy Dispersive Spectroscopy analyses of fossil and extant oothecae of mantises and cockroaches were performed in an attempt to solve their systematic placement within Dictyoptera and fossil allies, such as †Alienoptera. In addition to being the earliest known record of oothecae, this discovery moves the origin of this specialized reproductive strategy back by 100 million years. As direct fossil evidence, these specimens provide an important calibration and reference point that can inform future research on the origins and timing of diversification of the Dictyoptera.

On the value of Burmese amber for understanding insect evolution: Insights from †Heterobathmilla - an exceptional stem group genus of Strepsiptera (Insecta).

Burmese amber and amber from other periods and regions became a rich source of new extinct insect species and yielded important insights in insect evolution in the dimension of time. Amber fossils have contributed to the understanding of the phylogeny, biology, and biogeography of insects and other groups, and have also gained great importance for dating molecular trees. Another major potential is the documentation of faunal, floral and climatic shifts. Evolutionary transitions can be well-documented in amber fossils and can reveal anatomical transformations and the age of appearance of structural features. Here, using a new stem group species of Strepsiptera from Burmite, we evaluate this potential of amber insect fossils to assess the current phylogeny of Strepsiptera, with the main emphasis on the early splitting events in the stem group. Amber fossils have greatly contributed to the understanding of the evolution of Strepsiptera in the late Mesozoic and the Cenozoic. †Heterobathmilla kakopoios Pohl and Beutel gen. et sp. n. described here is placed in the stem group of the order, in a clade with †Kinzelbachilla (†Kinzelbachillidae) and †Phthanoxenos (†Phthanoxenidae). †Phthanoxenidae has priority over †Kinzelbachillidae, and the latter is synonymised. The superb details available from this new fossil allowed us to explore unique features of the antennae, mouthparts, and male copulatory apparatus, and to provide a phylogenetic hypothesis for the order. The younger †Protoxenos from Eocene Baltic amber was confirmed as sister to all remaining extinct and extant groups of Strepsiptera, whereas the position of the Cretaceous †Cretostylops in the stem group remains ambivalent. While the value of Burmite and amber from other periods has a recognized impact on our knowledge of the evolution in various lineages, this new fossil does not fundamentally change our picture of the phylogeny and evolution of early Strepsiptera. However, it offers new insights into the morphological diversity in the early evolution of the group.

Distinct preservational pathways of insects from the Crato Formation, Lower Cretaceous of the Araripe Basin, Brazil

This study compares two different preservation pathways of fossil insects in the lacustrine deposits of the Crato Formation, Lower Cretaceous (Aptian) of the Araripe Basin, northeastern Brazil. Three hundred seventy-seven specimens were examined and separated into ten taxonomic groups. Of this total, one hundred twenty-three are kerogenized insects, and two hundred fifty-four are pyritized insects. We carried out quantitative analyses of their taphonomic characters, such as body articulation, and morphological preservational quality (e.g. discernible eyes). Of all morphological categories, the thorax presented the highest degree of preservation quality, while the antennae had the lowest. Our statistical results show significant differences in the preservation quality of individual morphological categories among the insect taxa. We expected that mineralized insects would have lower preservational quality than the kerogenized ones, but instead found the opposite pattern to be true. Counter to the findings of other studies, we found that pyritized insects had higher preservation quality than kerogenized insects. The expected lower preservation fidelity of pyritized fossils occurs due to longer time exposed to microbial decay before final burial. Few studies have presented a quantitative comparison of preservational/biostratinomic patterns in different insect taxa, especially within the same geological setting. In this context, the Crato Formation presents an intriguing and unique opportunity to understand the taphonomic bias that results from two different preservation pathways of insects.

A geochemical model for the preservation of insects in the Crato Formation (Lower Cretaceous) of Brazil

The Crato Formation Lagerstätte of NE Brazil is well known for the exceptional preservation of its fossil assemblage. A wide variety of plants and animals are preserved with a high degree of fidelity, revealing structures of labile tissues at the micron scale, or even smaller. Chemical analyses and descriptions of replacement fabrics observed in insect fossils from the formation are here re-evaluated. Two mineral phases with three distinct fabrics are identified replacing soft tissues: 1) nano-crystalline high-fidelity pyrite replacements of insect epicuticle (pseudomorphed in goethite); 2) pyrite framboids and pseudoframboids obliterating original insect morphology (pseudomorphed in goethite); 3) globular replacements and encrustations of internal labile tissues in calcium phosphate. A revised taphonomic and geochemical model is presented that accounts for both the high fidelity of preservation and the micro-fabrics observed. In addition, we consider aspects of the depositional environment, including substrate consistency, water depth and light penetration. We conclude that the water depth was likely in excess of 50 m, but within the photic zone, and the sediment was bound by stratified microbial communities.

Facies interpretation and geochronology of diverse Eocene floras and faunas, northwest Chubut Province, Patagonia, Argentina

Abstract The Eocene Huitrera Formation of northwestern Patagonia, Argentina, is renowned for its diverse, informative, and outstandingly preserved fossil biotas. In northwest Chubut Province, at the Laguna del Hunco locality, this unit includes one of the most diverse fossil floras known from the Eocene, as well as significant fossil insects and vertebrates. It also includes rich fossil vertebrate faunas at the Laguna Fría and La Barda localities. Previous studies of these important occurrences have provided relatively little sedimentological detail, and radioisotopic age constraints are relatively sparse and in some cases obsolete. Here, we describe five fossiliferous lithofacies deposited in four terrestrial depositional environments: lacustrine basin floor, subaerial pyroclastic plain, vegetated, waterlogged pyroclastic lake margin, and extracaldera incised valley. We also report several new 40Ar/39Ar age determinations. Among these, the uppermost unit of the caldera-forming Ignimbrita Barda Colorada yielded a 40Ar/39Ar age of 52.54 ± 0.17 Ma, ∼6 m.y. younger than previous estimates, which demonstrates that deposition of overlying fossiliferous lacustrine strata (previously constrained to older than 52.22 ± 0.22 Ma) must have begun almost immediately on the subsiding ignimbrite surface. A minimum age for Laguna del Hunco fossils is established by an overlying ignimbrite with an age of 49.19 ± 0.24 Ma, confirming that deposition took place during the early Eocene climatic optimum. The Laguna Fría mammalian fauna is younger, constrained between a valley-filling ignimbrite and a capping basalt with 40Ar/39Ar ages of 49.26 ± 0.30 Ma and 43.50 ± 1.14 Ma, respectively. The latter age is ∼4 m.y. younger than previously reported. These new ages more precisely define the age range of the Laguna Fría and La Barda faunas, allowing greatly improved understanding of their positions with respect to South American mammal evolution, climate change, and geographic isolation.

Lichen mimesis in mid-Mesozoic lacewings.

Animals mimicking other organisms or using camouflage to deceive predators are vital survival strategies. Modern and fossil insects can simulate diverse objects. Lichens are an ancient symbiosis between a fungus and an alga or a cyanobacterium that sometimes have a plant-like appearance and occasionally are mimicked by modern animals. Nevertheless, lichen models are almost absent in fossil record of mimicry. Here, we provide the earliest fossil evidence of a mimetic relationship between the moth lacewing mimic Lichenipolystoechotes gen. nov. and its co-occurring fossil lichen model Daohugouthallus ciliiferus. We corroborate the lichen affinity of D. ciliiferus and document this mimetic relationship by providing structural similarities and detailed measurements of the mimic's wing and correspondingly the model's thallus. Our discovery of lichen mimesis predates modern lichen-insect associations by 165 million years, indicating that during the mid-Mesozoic, the lichen-insect mimesis system was well established and provided lacewings with highly honed survival strategies.

In situ occurrence of a gall midge (Insecta, Diptera, Cecidomyiidae) on fossilized angiosperm leaf cuticle fragments from the Pliocene sediments of eastern India

Abstract In situ preservation of fossil insect damage in plant fossils is an excellent tool to study the coevolution of flora and fauna through geological time, but finding both damage and the insect causing that damage in the same specimen is a very rare phenomenon. Galling is a common form of angiosperm leaf damage, which can be regarded as a kind of extended phenotype of the causal insects, essentially the gall midges, but galls usually lack remains of the insects themselves. Here we report the in situ occurrence of a gall midge (Insecta, Diptera, Cecidomyiidae) as well as its pupal exuviae on the abaxial cuticular surface of fossilized leaf cuticle fragments of Fabaceae leaves (cf. Albizia) that also bear galls, recovered from the latest Neogene (Rajdanda Formation, Pliocene) sediments of the Chotonagpur Plateau, Jharkhand, northeastern India. This Pliocene gall midge features well-preserved legs, segmented antenna with distinct and enlarged scape, elongate curved setae, and longer than broad terminal plate of the ovipositor lamellae. The in situ presence of a gall midge on a host fabaceous leaf cuticle indicates the existence of a host-ectoparasite relationship in the ancient warm and humid tropical monsoon-influenced forests of eastern India during the Pliocene. This is the first authentic fossil record of an in situ phytophagous insect of Cecidomyiidae from India, as well as southeast Asia. Although the identification of the recovered phytophagous insect associated with the fossil leaf cuticle is only possible to family level, this find reveals that such plant-insect relationships existed in the Pliocene of eastern India.

Ancient DNA preservation, genetic diversity and biogeography: A study of houseflies from Roman Qasr Ibrim, lower Nubia, Egypt

The optimal preservation of many Egyptian archaeological sites provides unique opportunities in the research into the evolution of synanthropic species, wild animals or plants, which benefit from close association with man-made human habitats. In this study we extracted and analysed ancient mitochondrial DNA (mtDNA) from three synanthropic insect species, two storage pests, Sitophilus granarius (Coleoptera: Curculionidae) (N = 8) and Trogoderma granarium (Coleoptera: Dermestidae) (N = 14), and the housefly Musca domestica (Diptera: Muscidae), (N = 14), from Roman Qasr Ibrim, an Egyptian frontier site located in lower Nubia. The impact of different experimental variables on ancient DNA recovery was also evaluated, confirming that it is possible to extract endogenous ancient DNA from desiccated specimens while preserving the insect exoskeleton. A phylogenetic comparison of the Qasr Ibrim housefly mtDNA-COI (COI) with modern housefly sequences, revealed that they were genetically similar to modern Egyptian, Near Eastern, Indian, Japanese, and US/Canadian populations. As the now cosmopolitan houseflies were transported by human populations alongside domestic animals and crops and may have aided the spread of disease, these findings provide important information for these processes. While limited by the resolution of the comparative databases, our research suggests the existence of biological invasions and links across the Red Sea from Egypt to the Arabian Peninsula, and exchanges between India and Egypt. We demonstrate the great potential of fossil insect aDNA for reconstructing biogeographic and diachronic species distribution and for better understanding past environments.

Fossil Genera in Elateridae (Insecta, Coleoptera): A Triassic Origin and Jurassic Diversification.

Insect fossils bear important information about the evolutionary history of the group. The fossil record of Elateridae, a large cosmopolitan beetle family, has been greatly understudied and the available data are often replete with ambiguity and uncertainty. The research of Elateridae evolution cannot be done without solid genus-group name concepts. In this study we provide an updated comprehensive summary of the fossil genera in Elateridae, including their systematic placement and information on the type species, gender, number of species, age range, and relevant bibliography. We list seven valid fossil genera in Agrypninae, one in Cardiophorinae, two in Dendrometrinae, five in Elaterinae, two in Negastriinae, one in Omalisinae, one in Pityobiinae, and 36 in Protagrypninae. Additional 19 genera are tentatively classified as Elateridae incertae sedis, and their placements are discussed. Further, we move genera Babuskaya Martins-Neto & Gallego, 2009, Cardiosyne Martins-Neto & Gallego, 2006, Fengningia Hong, 1984 and Gemelina Martins-Neto & Gallego, 2006 from Elateridae to Coleoptera incertae sedis. We also discuss the genera previously placed in Elateridae, which are currently not included in the family. The data on the fossil generic diversity suggest that Elateridae originated in the Triassic and rapidly diversified and became comparatively abundant through the Jurassic. We call for further research on the fossil Elateridae from various deposits in order to increase our knowledge on the origin, evolution, and palaeodiversity of the group.

Descriptions of two new species of Tarachoptera from Burmese amber (Insecta, Amphiesmenoptera: Tarachoptera)

During examination of new material of Burmese amber three individuals of Tarachoptera were discovered. The inclusions are sufficiently well preserved and allow identification and description of these rare, fossil insects. The species belong to the family Tarachocelidae and are described as Kinitocelis macroptera spec. nov. (†) and Retortocelis spicipalpia spec. nov. (†). The species and their preservations are described in detail, and photos and line drawings are provided for wing venation, head, mouthparts, and abdomen. The hitherto described species of Tarachoptera are summarized in a checklist.
 
 Taxonomic acts
 Kinitocelis macroptera Mey & Wichard, spec. nov. – urn:lsid:zoobank.org:act:E0B1624A-C69E-4B53-851F-4368AC21C614Retortocelis spicipalpia Mey & Wichard, spec. nov. – urn:lsid:zoobank.org:act:9778E7E2-EEFE-4DC5-B891-54DF114D525C

Revision of the Hylicellidae of the Late Triassic of Queensland (Hemiptera: Cicadomorpha: Hylicelloidea).

This extinct cicadomorphan family Hylicellidae was a significant element of the Late Triassic (Norian) hemipteran fauna of south-eastern Queensland, represented by the tegmina of five monotypic genera from the fossil insect localities at Mount Crosby, Denmark Hill and Dinmore. Of the five, Mesothymbris Evans, 1956, from Mount Crosby, has previously been re-examined. The present work revises the remaining four genera: Hylicella Evans, 1956, with Hylicella colorata Evans, 1956, Mount Crosby; Crosbella Evans, 1956 (= Mesocicadella Evans, 1956, syn. nov.), with Crosbella elongata Evans, 1956 (= Crosbella alata Evans, 1956, syn. nov. = Mesocicadella venosa Evans, 1956, syn. nov. = Mesocicadella punctata Evans, 1961, syn. nov.), Mount Crosby; Triassoscelis Evans, 1956, with Triassoscelis anomala Evans, 1956, Mount Crosby; and Mesocixiodes Tillyard, 1922, with Mesocixiodes termioneura Tillyard, 1922 (= Mesocixiodes brachyclada Tillyard, 1922, syn. nov.), Denmark Hill, Dinmore. The Hylicellidae remains poorly defined as is its generic composition, however, the four Queensland Triassic genera are quite distinct. Hylicella is distinguished by the partial fusion of CuA1 with M3+4, and the very large intra-medial cell, and Crosbella and Triassoscelis by the peculiar parallelogram-like CuA1 cell and the widened peripheral membrane at CuA. Triassoscelis differs from Crosbella in its broader, more squat wing shape, CuA fork in line rather than proximal to the M fork, and much less proliferated apical venation. Mesocixiodes is distinguished by the alignment of the crossvein field at the claval apex to form a fairly even series of long, sub-equal apical cells. On the basis of the proliferated and variable apical venation, the presence of weakly developed costal veinlets, and the fusion of M and CuA at a single point to close the basal cell, Crosbella and Triassoscelis, are ascribed to the subfamily Vietocyclinae. The relationships of the three other Queensland genera, Hylicella, Mesocixiodes, and Mesothymbris remain obscure, and they are retained in the undefined catch-all subfamily Hylicellinae. With the exception of the hindwing, Mesojassula marginata Evans, 1956, the revision of the cicadomorphan fauna of the Mount Crosby Formation is now complete, resulting in an inventory of five species of Dysmorphoptilidae, four of Hylicellidae and two of Archijassidae, with the dysmorphoptilid Dysmorphoptiloides elongata Evans, 1956, as the dominant species.

Two fossil thrips from Ethiopian amber (Thysanoptera) with description of Merothrips aithiopicus sp. n. (Thysanoptera: Merothripidae).

Amber has rarely been found in Africa and only a few samples with fossil inclusions are known (Kiefert et al. 2015). The most important fossiliferous find was reported from an outcrop at the north-western Plateau of Ethiopia a decade ago, revealing diverse inclusions of arthropods, plant remains, fungi and microorganisms (Schmidt et al. 2010). Initially, this amber was classified as originating from the mid-Cretaceous. Later studies, however, have raised questions about this determination and indicated a much younger age: Cenozoic, likely Miocene (Coty et al. 2016, Perrichot et al. 2016, Perrichot et al. 2018). The contradictory-and rather controversial discussed-new dating was based on spectroscopic analyses, revised palynological data and more comprehensive palaeoentomological results showing that insect fossils mostly belong to extant families and genera. In total, Schmidt et al. (2010) reported 22 insects from eight identified orders including two specimens of Thysanoptera: "an undetermined, wingless thrips" (obviously a larva) and a female associated with Merothripidae. A more detailed analysis of these specimens is the objective of the present study; regarding the larva, only a rough classification and description is given, as fossil larvae cannot be definitely associated with adult specimens.

A new fossil cercopoid from the middle Jurassic Ordos and Jiyuan basins, northern China (Hemiptera, Cicadomorpha)

ABSTRACT Here, a new genus and species, Qibinius maculatus gen. et sp. nov., is described and illustrated mainly based on forewing impressions from the Middle–Upper Jurassic Yan’an Formation in Yan’an City, Shaanxi Province, and the Yangshuzhuang Formation in Jiyuan City, Henan Province, which are located in Ordos Basin and Jiyuan Basin of northern China, respectively. Qibinius bears a long, multi-branched vein A1 of tegmen, adding valuable information on morphological diversity of Mesozoic Cicadomorpha, but raises some questions about taxonomic units. The new discovery enriches the documented palaeodiversity of fossil insects in the Yan’an and Yangshuzhuang formations of northern China, and also indicates that the Ordos and Jiyuan basins were interconnected in the mid-Jurassic.

<p><strong>A small gear to enhance the observation of amber inclusions</strong></p>

Paleoentomologists well know that the examination of fossil insects in amber is often complicated. Even if the amber is well-polished, the presence of small scratches at the surface and inner impurities generates reflections that limit observations. Prominent characters for taxonomy thus may not be visible even when preserved. Several solutions have been proposed to enhance the observation of fossil insects in amber. Most of them aim at limiting the number of optical medium interfaces, and thus reducing optical artefacts such as refraction and reflection. For example, amber may be embedded in Canada balsam or artificial resins (Azar & Nel, 1998; Green, 2001; Sidorchuk, 2013; Penney & Jepson, 2014; Sidorchuk & Vorontsov, 2018). However, these methods limit viewing angles and thus the observation of characters, are technically challenging and often irreversible. Another type of method is to immerse the piece of amber in a liquid with a refractive index as close as possible to the amber, such as sugared water, or oils (Sidorchuk, 2013). In this case, the interface between the objective lens and the amber is the coverslip that is placed on the surface of the liquid in order to avoid reflection on the water surface. Compounding the difficulty in observation is that an immersed piece of amber is observable only from one angle at a time, and the whole setting must be dismantled and reassembled to manually change the observation angle, which can result in a lengthy procedure.