Kundrata, R. | bioRxiv Science

bioRxiv2025

Morphology of male genitalia and legs reveals the classification of Mesozoic Zoraptera (Insecta)

Zoraptera is a small insect order with less than 50 described species from mostly tropical and subtropical regions of the World. The current system of extant Zoraptera is based on the results of molecular phylogeny combined with the morphology of male genitalia, and supplemented by the characters on the male abdomen and a number of metatibial spurs. However, fossil representatives of Zoraptera have not yet been classified into the modern system and most of them remained in the collecting genus Zorotypus Silvestri, 1913, because the genitalia were not observable or examined in detail. In this study, for the first time, we describe and critically evaluate the male genitalia and other principal diagnostic characters of all available Mesozoic Zoraptera. Our results lead to the first proposal of the generic classification of Mesozoic Zoraptera. We describe two new genera, Cretozoros gen. nov. and Burmazoros gen. nov., reinstate Paleospinosus Kaddumi, 2005, stat. restit. from synonymy with the subgenus Octozoros Engel, 2003 (in Zorotypus), and elevate Octozoros Engel, 2003 to a genus level. Cretozoros gen. nov., Paleospinosus stat. restit. and Octozoros stat. nov. are classified in Spiralizoridae: Latinozorinae, while Burmazoros gen. nov. and Xenoburmiticus Engel & Grimaldi, 2002 are classified in Zorotypidae: Zorotypinae. Altogether, it was possible to classify nine out of the 11 currently recognized species of Mesozoic Zoraptera. Zorotypus hukawngi Chen & Su 2019 is synonymized with Cretozoros acanthothorax (Engel & Grimaldi, 2002), comb. nov. and Zorotypus hirsutus Mashimo, 2018 is synonymized with Octozoros robustus (Liu, Zhang, Cai & Li, 2018), stat. restit., comb. nov., which is simultaneously restituted from the synonymy with Octozoros cenomanianus (Yin, Cai & Huang, 2018), comb. nov. The classification of Mesozoic Zoraptera into the modern system enables us to better understand the diversity of their internal lineages during the early evolution of this enigmatic insect order.

paleontology↗

bioRxiv2021

Integrated phylogenomics and fossil data illuminate the evolution of beetles

With over 380,000 described species and possibly several million more yet unnamed, beetles represent the most biodiverse animal order. Recent phylogenomic studies have arrived at considerably incongruent topologies and widely varying estimates of divergence dates for major beetle clades. Here we use a dataset of 68 single-copy nuclear protein coding genes sampling 129 out of the 194 recognized extant families as well as the first comprehensive set of fully-justified fossil calibrations to recover a refined timescale of beetle evolution. Using phylogenetic methods that counter the effects of compositional and rate heterogeneity we recover a topology congruent with morphological studies, which we use, combined with other recent phylogenomic studies, to propose several formal changes in the classification of Coleoptera: Scirtiformia and Scirtoidea sensu nov., Clambiformia ser. nov. and Clamboidea sensu nov., Rhinorhipiformia ser. nov., Byrrhoidea sensu nov., Dryopoidea stat. res., Nosodendriformia ser. nov., and Staphyliniformia sensu nov., alongside changes below the superfamily level. The heterogeneous former superfamily Cucujoidea is divided into three monophyletic groups: Erotyloidea stat. nov., Nitiduloidea stat. nov., and Cucujoidea sensu nov. Our divergence time analysis recovered an evolutionary timescale congruent with the fossil record: a late Carboniferous origin of Coleoptera, a late Paleozoic origin of all modern beetle suborders, and a Triassic-Jurassic origin of most extant families. While fundamental divergences within beetle phylogeny did not coincide with the hypothesis of a Cretaceous Terrestrial Revolution, many polyphagan superfamilies exhibited increases in richness with Cretaceous flowering plants.

zoology↗