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We report a fossil ootheca of Dictyoptera from mid-Cretaceous Burmese (Myanmar) amber. This ootheca resembles those of extant mantises, particularly Chaeteessa, and it is provisionally identified to Mantodea. Whilst Blattodea (Blattaria and Isoptera, or ‘true’ cockroaches and termites) are ruled out as the owner of this ootheca, Alienoptera and basal Dictyoptera remain possible. This is the first fossil described of the mantis-type ootheca, and also direct evidence of Dictyoptera in Cretaceous.

Here we describe a new corydiid cockroach, Nodosigalea burmanica gen. et sp. nov., from the middle Cretaceous Burmese amber. The well-preserved specimens exhibit a typical habitus of Corydiidae, and are characterized by nodulous pronotum, distinct wing venation and unique tarsi, the hind ones of which have different ventral structures from the fore- and midlegs. The combination of adhesive fore- and midtarsi and propulsive hindtarsi suggests a particular life style of the new genus. The phylogenetic position of the new genus within Corydiidae, however, is uncertain.

Here we describe a new praying mantis species, Burmantis hexispinea sp. nov., from middle Cretaceous Burmese amber. The new species differs from other species of Burmantis in the forefemoral spination with six large spines, instead of five. Although not the first adult of Burmantis, the holotype provides exclusive adult morphology of this genus: the wing venation is typical of Mantodea, and male terminalia are symmetrical or nearly symmetrical, with long cerci and styli. The holotype exhibits intraspecific variation in the forefemoral spination between the leg pair, and this suggests caution when proposing new taxa based on such characters.

A second blattoid species, Cercoula brachyptera gen. et sp. nov. is described from Cretaceous amber. It is placed in Blattoidea because of the combination of bivalvate female subgenital plate and type-A fore-femoral spination. Its relatively small size, and small, slender, pod-like cerci, suggest that the new species is a stem member of Blattoidea. Cercoula brachyptera is the first fossil of brachypterous cockroach. Since wing reduction might be a response of cockroaches to the arid environment, C. brachyptera might indicate an arid microenvironment or a dry season, or even contribute to the possibility of an arid palaeoclimate of the Myanmar amber locality. (C) 2020 Elsevier Ltd. All rights reserved.

Nocticolidae are delicate cockroaches, characterized by simple but unique wing venation. They are included in Corydioidea with Corydiidae. No fossil of this family was reported. Here we describe a stem member of Nocticolidae, Crenocticola burmanica gen. et sp. nov., from mid-Cretaceous Burmese amber. Its morphology appears plesiomorphic for Nocticolidae, and exhibits transitional form between crown Nocticolidae and Latindiinae (in Corydiidae). Placing Crenocticola in stem Nocticolidae is confirmed by a preliminary morphological phylogeny based on 28 non-genital characters. We use Crenocticola and published fossils to calibrate dating analyses of Corydioidea under autocorrelated TK02 relaxed clock model in MrBayes, and the analyses in turn test the power of Crenocticola as a node calibration. The dataset comprises published DNA (12S, 16S, 18S and 28S) of 19 ingroup taxa of Corydioidea, and eight outgroup taxa including termites. As a result, Crenocticola is too young to be an effective calibration. It is suppressed by the oldest fossil of termites, which may also be crucial in previous studies provided that unjustified fossil calibrations (e.g. ‘roachoids’) are excluded. We compare two approaches to applying fossil calibrations: 1) in-analytical calibration, i.e. incorporating the fossil age in prior settings, and 2) post-analytical calibration, i.e. adjusting the fixed prior so that the estimated age does not conflict with the fossil age. In-analytical calibration may underestimate the age, whilst post-analytical calibration yields better estimates. Our dating analyses suggest that crown Corydioidea likely originated in the Late Triassic or Early Jurassic. Questionable genera in Nocticolidae are briefly discussed.