Abstract

Archaeognatha (Machilida plus †Monura), with ~450 extant species worldwide, represent a key lineage for the understanding of insect evolution. In a recently published phylogenetic analysis on Archaeognatha, based on a total-evidence approach, a Machilidae key fossil (Gigamachilis triassicus) from the Middle Triassic Lagerstätte of Monte San Giorgio and a representative of †Monura (Dasyleptus triassicus) from the same fossiliferous site, were not considered. In this study, the phylogenetic analyses performed by Zhang et al. (2018) using Maximum Parsimony and Bayesian inference were repeated including these two key taxa; in addition, Tricholepidion gertschi and Lepisma saccharina were included as representative of Zygentoma. In the total-evidence Bayesian analysis, †Monura was found to be paraphyletic, while in the maximum parsimony analysis, performed only on morphological characters, they were monophyletic. Moreover, the attribution of G. triassicus to Machilidae is now confirmed by these analyses, indicating that members of the extant group of Machilidae were already present in the Middle Triassic, at least ~100 My before the previous estimate.