Genomic inferences in a thermophilous grasshopper provide insights into the biogeographic connections between northern African and southern European arid‐dwelling faunas

Aim Although thermophilous and arid-dwelling relict biotas constitute a singular component of European biodiversity high conservation value, we still largely ignore their biogeographic history. In this study, investigate the geographical diversification Maghrebian-Levantine crested grasshopper its colonization semiarid habitats southeastern Iberia to gain insights into historical processes underlying connections between northern African southern faunas. Location Mediterranean region. Taxon Crested grasshoppers Dericorys millierei carthagonovae (Orthoptera: Dericorythidae). Methods We used genomic data (ddRAD-seq) quantify genetic structure populations, infer phylogenetic relationships among them, estimate divergence times, elucidate demographic accompanying Iberia. Genomic-based inferences were interpreted in light eustatic sea-level reconstructions species’ range dynamics derived from palaeodistribution modelling at fine temporal resolution. Results Clustering analyses showed strong phylogenomic inference revealed that Iberian populations are nested within Maghrebian clade. Molecular dating indicated all lineages diverged during Pleistocene (<1.6 Ma), with point estimates coinciding glacial periods sea level drops. According modelling, species experienced severe contractions coldest stages Pleistocene. Main conclusions Our results indicate Peninsula likely took place marked drops characterizing high-amplitude climatic oscillations late Quaternary (<0.5 which considerably reduced overseas distances landmasses might have eased transmarine exchanges terrestrial These findings emphasize relevance Maghreb region as source corroborate post-Messinian two continents despite barrier effect Sea.