Morpho-Molecular Discordance and Cryptic Diversity in Jumping Bristletails: A Mitogenomic Analysis of Pedetontus silvestrii (Insecta: Archaeognatha: Machilidae)

Archaeognatha (bristletails) represent an evolutionarily significant but understudied insect group. Notably, the morphological identification method proposed by Mendes for Archaeognatha has certain limitations, which may lead to the underestimation or misidentification of some cryptic species. To address this issue, we employed an integrated strategy that combines morphological and molecular identification methods. Therefore, this study aimed to (1) identify cryptic diversity within <i>Pedetontus silvestrii</i> using mitogenomic data; (2) clarify phylogenetic relationships among Archaeognatha lineages; and (3) estimate divergence times for key taxonomic splits. We analyzed mitochondrial genomes from six <i>P. silvestrii</i> populations (Liaoning, Jilin, and Hebei Provinces) alongside 14 published Archaeognatha genomes. Key findings include the following: (1) Integrative analyses of genetic distances, phylogenetic reconstruction, bPTP-based molecular species delimitation, and divergence time estimation collectively revealed four evolutionarily distinct lineages within <i>P. silvestrii</i>. (2) Machilidae and Machilinae were non-monophyletic, whereas Petrobiellinae showed close affinity to Meinertellidae. (3) Archaeognatha originated ~301.19 Mya (Late Carboniferous); the Machilinae-Petrobiinae split occurred approximately 153.99 Mya (Jurassic). This study underscores the critical importance of mitogenomic analysis in elucidating cryptic biodiversity, while emphasizing the necessity of integrating morphological identification with molecular characterization for comprehensive species delineation in future taxonomic investigations.