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The non-marine bivalve Ferganoconcha occurred widely in palaeolakes in the high-middle latitude of northern China, Siberia and Central Asia during the Early and Middle Jurassic and was an important member of these lacustrine ecosystems. The diagnostic features and phylogenetic position of Ferganoconcha are still under debate. Here, based on nearly one hundred of Ferganoconcha specimens from the lacustrine and fluvial facies of the Junggar Basin in northwestern China, it is clearly shown that its most important distinctive features are the thin and flatted to weakly inflated shell covered with wrinkled ornament and the ligament is well-developed. This kind of shell indicate that the Ferganoconcha is a weak suspension feeder, burrowing rapidly and living in fine-soft substrata of the 'low energy' environments. In addition, we conclude that the dispersal pattern of the Ferganoconcha generally followed the cool to temperate and humid paleoclimate zone in northern China during the Early to Middle Jurassic, making the genus a possible palaeclimatic indicator. [ABSTRACT FROM AUTHOR]

The new genus and species, Jurassephemera zhangi gen. et sp. nov., belonging to the extinct family Sharephemeridae (Ephemeroptera: Mesephemeroidea), is established from the late Early Jurassic interval of the Shiti Formation of Guangxi Zhuang Autonomous Region, South China. The new genus and species is characterised by its moderate size; small head with reduced compound eyes; body with ten abdominal segments; round-triangular forewing shape; vein R dividing three times, forming five veinlets and three triads; veins MA, MP, and CuA straight, all basally forking once with single triads between; crossveins well developed; and hind wing oval, much smaller than forewing, with veins generally radial and single. SEM observations also reveal that crossveins are much more developed than previously recognised under optical illumination. The forewing venation of all sharephemerid genera is compared. The first report of this family in China herein increases the diversity and palaeogeographic distribution of Sharephemeridae. [ABSTRACT FROM AUTHOR]

A distinct coal break occurs widely in the late Early Jurassic in Central Asia, the cause of which, however, is still debated largely due to the uncertainty of its age constraint. In the Junggar Basin of northwestern China, this coal break coincides with the Sangonghe Formation, which is well exposed along the basin margins, and is mainly composed of lacustrine deposits rich in a variety of fossils, including plants, pollens and spores, bivalves, clam shrimps, insects and some vertebrates. Here we name them as the Sangonghe biota and review their biostratigraphic framework. The Sangonghe biota constrains the Sangonghe Formation to the late Pliensbachian to the early Aalenian. Abundant thermophilous plants and Classopollis, together with frequent occurrences of red beds and carbonate nodules in the middle part of the Sangonghe Formation, are indicative of an arid climate in Central Asia at that time. This arid interlude should be responsible for the coal break, which may be related to the global warming in the early Toarcian. However, more precise dating evidence is needed to substantiate this. [ABSTRACT FROM AUTHOR]

As an important combination of behaviour and pattern in animals to resemble benign objects, biolog ical mimesis can effectively avoid the detection of their prey and predators. It at least dates back to the Permian in fossil records. The recognition of mimesis within fossil, however, might be subjective and lack quantitative analysis being only based on few fossils with limited information. To compensate for this omission, we propose a new method using a Siamese network to measure the dissimilarity between hypothetical mimics and their models from images. It generates dissimilarity values between paired images of organisms by extracting feature vectors and calculating Euclidean distances. Additionally, the idea of 'transfer learning' is adopted to fine-tune the Siamese network, to overcome the limitations of available fossil image pairs. We use the processed Totally-Looks-Like, a large similar image data set, to pretrain the Siamese network and fine-tune it with a collected mimetic-image data set. Based on our results, we propose two recommended image dissimilarity thresholds for judging the mimicry of extant insects (0–0.4556) and fossil insects (0–0.4717). Deep learning algorithms are used to quantify the mimicry of fossil insects in this study, providing novel insights into exploring the early evolution of mimicry. [ABSTRACT FROM AUTHOR]

The second species of Saltissus, as the first mimarachnid planthopper, is herein described from the upper Weald Clay Formation, Smokejacks brickworks, England. Saltissus fennahi Luo, Liu et Jarzembowski sp. nov. can be distinguished from the type species Saltissus eskovi Shcherbakov, 2007 due to the tegmen being more than 20 mm long, stem Pc+CP merged with margin at less than 1/10th of tegmen length, stem ScP+R forked beyond the fusion of Pcu+A1, and branch A1 curved strongly at base. The distribution and tegminal colour pattern of Mimarachnidae are briefly discussed. [ABSTRACT FROM AUTHOR]

The damselfly superfamily Coenagrionoidea is the largest zygopteran group, comprising three-fifths of all extant damselfly species. The Mesozoic fossil record of this superfamily is sparse, whilst it is relatively common in Burmese amber. A new coenagrionoid family, Burmacoenagrionidae Zheng et al., fam. nov., is established here based on four new species in three new genera: Burmacoenagrion pretiosus Zheng et al. gen. et sp. nov., Burmachistigma cheni Zheng et al. gen. et sp. nov., Electrocoenagrion elongatum Zheng et al. gen. et sp. nov. and Electrocoenagrion forficatum Zheng et al. gen. et sp. nov. The previously described damselfly genus, Burmagrion Möstel et al., 2017, is transferred to this family. Burmacoenagrionidae Zheng et al. fam. nov. has a long pterostigma covering 3-5 cells, pigmented wings and a sigmoidally curved RA and RP1 distal of the pterostigma, differing from other coenagrionoid damselflies. Until now, this is the most diverse damselfly family reported from Burmese amber, showing that the Coenagrionoidea were already highly diversified 100 million years ago. http://zoobank.org/urn:lsid:zoobank.org:pub:DAB9700E-2F21-4BC7-97A0-41569DA4898A [ABSTRACT FROM AUTHOR]

Odonatans are quite rare in the fossil record compared with the other insects, especially in Cretaceous amber inclusions. The extant family Platystictidae is one of the most diverse Zygoptera, but short of fossil records. In this paper, a new species, Mesosticta davidattenboroughi sp. nov., is described from mid-Cretaceous Burmese amber, representing the third-known fossil species of Platystictidae. Mesosticta davidattenboroughi sp. nov. has a long IR1 beginning one cell distal of the base of RP2, confirming the previous attribution of Mesosticta Huang, Azar, Cai & Nel, 2015 to Platystictidae. It differs from other species of Mesosticta in having a long IR1 and a basally crossed subdiscoidal cell. The fossil genus Mesosticta shares the diagnostic characters of the modern platystictid genera, viz. a basally recessed ‘CuP’ (shared by all species), a very long IR1 (only in Mesosticta davidattenboroughi sp. nov.), and a specialized subdiscoidal area mostly rhomboidal in shape (only in Mesosticta electronica Zheng, Zhang, Chang & Wang, 2016). Based on the platystictid damselflies from Burmese amber, a new subfamily Mesostictinae subfam. nov. is established. Mesostictinae subfam. nov. represents the first fossil group of modern platystictid damselflies, documenting the appearance of Platystictidae as early as mid-Cretaceous. It differs from modern Platystictidae by the presence of fewer postnodal and postsubnodal crossveins, a short MP, the base of RP2 being nearer to the subnodus and the nodus lying more distally. http://zoobank.org/urn:lsid:zoobank.org:pub:6669DBCD-F2EF-4C84-9623-BD33142AD36B [ABSTRACT FROM AUTHOR]

Amber inclusions have been studied for several centuries, but true dragonflies are extremely rare, with only several poorly preserved wings recorded. In Burmese amber, odonatans are relatively diverse, but true dragonflies are still rare. An excellently preserved true dragonfly, Burmagomphides electronica Zheng, Nel & Wang gen. et sp. nov., representing the new family Burmagomphidae Zheng, Nel & Wang fam. nov., is described here from Cretaceous Burmese amber. This is the first well-preserved true dragonfly with complete wings in this amber. It is attributed to the clade Oligophlebiata because it has symmetrical RP branches at the midfork and a well-developed trigonal planate as in the clade Hagenioidea, and the vein CuAa distinctly shortened with reduced pectinate branching as in Brevicubitalia; it differs, however, from the latter two in having a narrow hind wing base. [ABSTRACT FROM AUTHOR]

Mesozoic fossils of longhorn beetles, leaf beetles and other Chrysomeloidea are extremely rare, and little is known about the early evolutionary history of this extraordinarily diverse superfamily of beetles. Here we report the earliest known fossil cerambycid,Cretoprionus liutiaogouensisgen. et sp. nov., from the Lower Cretaceous Yixian Formation of China.C. liutiaogouensisbears several features characteristic of the extant subfamily Prioninae, including a large and robust body, absence of a stridulatory plate on the mesonotum, pseudotetramerous tarsi, mouthparts projecting forwards, and lateral carinae on the prothorax. It represents the only definite Mesozoic record of Cerambycidae, and extends the time of origin of the Prioninae as early as the Early Cretaceous. We incorporate two new calibration points as minimum constraints on the age of (1) Prioninae + Parandrinae and (2) Bruchinae using data from a recent molecular phylogenetic study of Chrysomeloidea, to reconstruct divergence times among the major lineages of Chrysomeloidea. Our analyses suggest that most chrysomeloid families appeared in the Jurassic and diversified over the course of the Cretaceous, a scenario consistent with the codiversification of Chrysomeloidea and their (predominantly) angiospermous hosts; however, the phylogeny of Chrysomeloidea remains incompletely resolved, and further elucidation of timing and patterns of chrysomeloid macroevolution will require additional study. http://zoobank.org/urn:lsid:zoobank.org:pub:0FF28F2E-026E-4408-9CF6-D61B6197548E [ABSTRACT FROM AUTHOR]