Termites (Isoptera) are among the most ecologically ubiquitous of terrestrial eusocial insects and provide an attractive environment for symbionts, which have evolved numerous times independently, and in lineages as diverse as millipedes and beetles. Previous studies reported the discovery of unequivocal termitophily in mid-Cretaceous amber from northern Myanmar, providing evidence that pushed the origin of termitophily back into the Mesozoic. Here we report the discovery of two more pieces of Cretaceous amber containing individuals of the trichopseniine rove beetle Cretotrichopsenius burmiticus Cai et al., 2017 (Staphylinidae: Aleocharinae: Trichopseniini) preserved together with their potential host termites, providing further evidence regarding the association between these two insect lineages. Two new termite species and genera are described as putative hosts for C. burmiticus: Arceotermes hospitis Engel & Jiang, gen. et sp. nov. and Tanytermitalis philetaerus Engel & Cai, gen. et sp. nov. Each is included in a new family, Arceotermitidae Engel, fam. nov. (type genus: Arceotermes Engel & Jiang, gen. nov.), and Tanytermitidae Engel, fam. nov. (type genus: Tanytermes Engel et al., 2007). In order to better characterize these two families the classification of lower Isoptera and clade Xylophagodea (= Cryptocercidae + Isoptera) is emended with the following new taxa: Idanotermitinae Engel, subfam. nov.; Melqartitermitidae Engel, fam. nov.; Mylacrotermitidae Engel, fam. nov.; Krishnatermitidae Engel, fam. nov.; Cosmotermitinae Engel, subfam. nov.; Hodotermopsinae Engel, subfam. nov.; Artisoptera Engel, minord. nov.; Cryptocercaptera Engel, infraord. nov. Lower termites were remarkably diverse during the mid-Cretaceous but declined in diversity considerably by the Palaeogene. The fossil rove beetle Cretotrichopsenius Cai et al., 2017 currently provides the earliest definitive evidence of termitophily and the complex association between rove beetles and termites.

Background: Flowering plants (angiosperms) dominate most global ecosystems today, but their rapid Cretaceous diversi cation has remained poorly understood ever since Darwin referred to it as an 'abominable mystery'. Although numerous Cretaceous fossil owers have been discovered in recent years, most are represented by incomplete charcoali ed fragments that do not preserve delicate structures such as complete petals and surface textures, which means that their similarity to living forms is often di cult to discern. The scarcity of information about the ecology of early angiosperms makes it di cult to test hypotheses about the drivers of their diversi cation. Among other factors, frequent res in the Cretaceous have been postulated as having possibly facilitated the rise of angiosperms. However, to date no early fossil angiosperms displaying re-adapted traits have been known, making the role of re in shaping Cretaceous oras uncertain.Results: We report the discovery of two exquisitely preserved fossil ower species, one identical to the in orescences of the extant crown eudicot genus Phylica and the other recovered as a sister group to Phylica, both preserved as inclusions in Cretaceous amber from northern Myanmar (~99 Ma). These specialized ower structures, named Phylica piloburmensis sp. nov. and Eophylica priscastellata gen. et sp. nov., were adapted to surviving frequent wild res, providing the earliest evidence of re-resistance in angiosperms. The fossils suggest that re was a signi cant selective force in Cretaceous angiosperm oras and that adaptations to re resistance in some eudicot clades have been conserved for at least 99 Ma. This morphological stasis encompasses a range of oral characters, including the production of 'pseudo-owers', and characteristic fruit and pollen architecture. Given its morphological distinctiveness,

Structural colours, nature's most pure and intense colours, originate when light is scattered via nanoscale modulations of the refractive index. Original colours in fossils illuminate the ecological interactions among extinct organisms and functional evolution of colours. Here, we report multiple examples of vivid metallic colours in diverse insects from mid-Cretaceous amber. Scanning and transmission electron microscopy revealed a smooth outer surface and five alternating electron-dense and electron-lucent layers in the epicuticle of a fossil wasp, suggesting that multilayer reflectors, the most common biophotonic nanostructure in animals and even plants, are responsible for the exceptional preservation of colour in amber fossils. Based on theoretical modelling of the reflectance spectra, a reflective peak of wavelength of 514 nm was calculated, corresponding to the bluish-green colour observed under white light. The green to blue structural colours in fossil wasps, beetles and a fly most likely functioned as camouflage, although other functions such as thermoregulation cannot be ruled out. This discovery not only provides critical evidence of evolution of structural colours in arthropods, but also sheds light on the preservation potential of nanostructures of ancient animals through geological time.

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