Alienopterix Mlynský et al., 2018 complex in North Myanmar amber supports Umenocoleoidea/ae status

Alienopterix santonicus sp. n., a metallic cockroach from the Late Cretaceous ajkaite amber (Bakony Mts, western Hungary) documents Alienopteridae within the Mesozoic Laurasia

Cockroaches (Blattaria s. str.) were documented from numerous amber localities around the world, representing both extinct and extant families. Alienopteridae is an extinct cockroach family known only from the Cretaceous of Gondwana (Brazil, Botswana, Myanmar amber) and the Cenozoic of North America. Alienopterix santonicus sp. n. from the Late Cretaceous amber of the Ajka Coal Formation (Bakony Mts, western Hungary) extends the rich geographical distribution of the family into Laurasia during the Mesozoic. As a member of the presumably pollinator cohort Alienopteridae, this species could have played an important role in the Ajka Coal ecosystem during the Santonian. The microrectangular structures of the forewing suggest that the new species likely possessed a metallic colouration already known from the group. Combined with the disruptive body pattern this could have served as an advanced camouflage. The microrectangular structures of the forewing were compared to integument microstructures of extant insects with metallic colouration. Various arthropod taxa are already known from ajkaite, and the new discovery further emphasizes the importance of this amber.

Predators or Herbivores: Cockroaches of Manipulatoridae Revisited with a New Genus from Cretaceous Myanmar Amber (Dictyoptera: Blattaria: Corydioidea)

Manipulator modificaputis Vršanský and Bechly, 2015 (Manipulatoridae, Corydioidea) is a purported predatory cockroach from Cretaceous Myanmar amber, based on a single male. It is distinctive by the nimble head, elongate pronotum and legs, and particularly by the extraordinarily long maxillary palpi. In the present study, we redescribe Manipulator modificaputis based on six new fossils including males and females, and comment on the original description. The closely related Manipulatoides obscura gen. & sp. nov. is proposed on the basis of five fossils, including males and females. It differs from Manipulator in weaker spination of the legs, including the type-C forefemoral spination instead of the type-A of Manipulator. Some undetermined adults and nymphs are also described. We discuss the ethology of Manipulatoridae and speculate that they might feed on flowers. They are unlikely to be specialized predators since they lack necessary weaponry for capturing prey; in contrast, their unique morphotype appears to be suitable for efficient foraging and locomotion amid flowering twigs. The possibility of being kleptoparasites of the spider-web is also discussed. In addition, regenerated four-segmented tarsi are found from the new species.

Aposematic coloration from Mid-Cretaceous Kachin amber

Aposematic coloration is among the most diverse antipredator strategies, which can signal unpleasantness of organisms to potential predators and reduce the probability of predation. Unlike mimesis, aposematic coloration allows organisms to warn their predators away by conspicuous and recognizable colour patterns. However, aposematism has been a regular puzzle, especially as the long-term history of such traits is obscured by an insufficient fossil record. Here, we report the discovery of aposematic coloration in an orthopteran nymph from Mid-Cretaceous Kachin amber (99 million years old). It is attributed to the extinct family Elcanidae and erected as a new genus identified by conspicuous dark/light-striped coloration, four apical spurs on the metatibia, a two-segmented metatarsus and unsegmented stylus. It represents the first fossil orthopteran preserved with aposematic coloration from the Mesozoic, demonstrating that orthopterans had evolved aposematism by the Mid-Cretaceous. Our findings provide novel insights into the early evolution of anti-predator strategies among orthopterans. Together with mimesis, debris-carrying camouflage and aposematism previously reported, our findings demonstrate the relative complexity of prey-predator interactions in the Mesozoic, especially in the Mid-Cretaceous Kachin amber forest. This article is part of the theme issue 'The impact of Chinese palaeontology on evolutionary research'.

Reconstructing the ecology of a Cretaceous cockroach: destructive and high-resolution imaging of its micro sensory organs

Animals highly depend on their sensory organs to detect information about their surrounding environment. Among animal sensory organs, those of insects have a notable ability to detect information despite their small size, which might be, therefore, one of the reasons for the evolutionary success of insects. However, insect sensory organs are seldom fossilized in sediments due to their small size and fragility. A potential solution for this problem is the study of exceptionally well-preserved fossil material from amber. Unfortunately, the resolution of existing non-destructive analysis is insufficient to observe details of these micro sensory organs even with amber preservation. Here, we focus on the analysis of the micro sensory organs of an extinct male cockroach (Huablattula hui Qiu et al., 2019) in Cretaceous amber by combining destructive and non-destructive methods. Compared to extant species inhabiting dark environments, H. hui has relatively large compound eyes, and all the antennal sensilla for detecting multimodal information observed here are fewer or smaller. The characteristics of these sensory organs support the diurnality of the bright habitats of H. hui in contrast to many extant cockroaches. Like extant male mantises, grooved basiconic type sensilla exist abundantly on the antenna of the fossilized specimen. The abundance of grooved basiconic sensilla in mantid males results from using sex pheromones, and therefore, H. hui may have likewise used mantis-like intersexual communication. These lines of evidence suggest that the ecology and behavior of Cretaceous cockroaches were more diverse than those of related extant species.

A new cockroach (Blattodea, Corydiidae) with pectinate antennae from mid-Cretaceous Burmese amber

A new species of fossil cockroach, Fragosublattapectinata gen. et sp. nov., is described from mid-Cretaceous Burmese amber. The new species is assigned to the family Corydiidae based on the following combination of characters: pronotum with tubercles, tegmina obovate with smallish anal region and spinules on the antero-ventral margin of the front femur (type C1). The new species is the second reported cockroach with ramified antennae. This finding broadens the diversity of Blattodea in mid-Cretaceous Burmese amber and provides further evidence of convergent evolution for antennal structures among different insect lineages.