中国科学院南京地质古生物研究所机构知识库

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. (C) 2019 Elsevier Ltd. All rights reserved.