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

TL;DR

This study classifies Mesozoic Zoraptera fossils using male genitalia and other features, leading to new genera and better understanding of their evolution.

Contribution

The first classification of Mesozoic Zoraptera fossils into a modern system using detailed morphological analysis.

Findings

Nine of 11 Mesozoic Zoraptera species were classified into modern taxonomy.

Two new genera, Cretozoros and Burmazoros, were described.

Phylogenetic relationships were evaluated using ancestral character state reconstruction.

Abstract

The current classification 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 the number of metatibial spurs. However, fossil representatives of Zoraptera have not yet been classified into the modern system, and most of them remain in the catch-all genus Zorotypus Silvestri, 1913, because the genitalia are either not observable or have not been 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 have led to the first proposal of a 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 the genus level. Cretozoros gen. nov., Paleospinosus Kaddumi, 2005, stat. restit., and Octozoros stat. nov. are classified in Spiralizoridae: Latinozorinae, whereas Burmazoros gen. nov. and Xenozorotypus Engel & Grimaldi, 2002 are classified in Zorotypidae: Zorotypinae. Altogether, it was possible to classify nine of the 11 currently recognized species of Mesozoic Zoraptera. To evaluate the phylogenetic relationships of fossil zorapterans, including the newly established taxa, we estimated the evolutionary histories of selected morphological features using ancestral character state reconstruction. The classification of Mesozoic Zoraptera within the modern system enables us to better understand the early evolution of this insect order.

The online version contains supplementary material available at 10.1186/s12983-025-00595-x.

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