Phylogenetic Insights and a New Distribution Map for Chile's Endemic <i>Virilastacus</i> Crayfishes

ABSTRACT Freshwater crayfishes of the South American family Parastacidae include the Chilean‐endemic genus Virilastacus , currently comprising four described species. Despite their ecological importance and restricted distributions, the genetic diversity, phylogenetic relationships, and species boundaries within Virilastacus remain poorly understood. Here, we analyze mitochondrial DNA (COI) sequences from populations across the genus's known range in southern Chile to assess species limits, divergence times, and geographic structure. Phylogenetic analyses and multiple single‐locus species delimitation methods support the identification of five candidate species, comprising the four currently recognised species and a newly identified lineage, Virilastacus sp. ‘Calfuco’. Divergence time estimates place the origin of Virilastacus in the Middle Oligocene, indicating an ancient evolutionary history. We also report an expanded range for V. jarai , a narrower distribution for V. araucanius , and strong geographic structuring across the genus. These findings highlight previously overlooked diversity in Virilastacus and emphasise the need for further integrative taxonomic and conservation assessments.