Revealing patterns of endemism in the transatlantic family Chelodesmidae (Polydesmida: Diplopoda)

With fossil records dating back to the Silurian/Late Ordovician, millipedes stand out as one of the earliest terrestrial animal groups. Their limited vagility and high endemism make them valuable tools for formulating and testing biogeographic hypotheses, including those related to macro-vicariance events. Among the order Polydesmida, the family Chelodesmidae displays an intriguing transatlantic distribution, suggesting a Gondwanan origin. Despite this, the evolutionary relationships and biogeography of the family remain largely unknown. In this study, we explore areas of endemism (AEs) for Chelodesmidae using endemicity analysis (NDM/VNDM), utilising a data set of 1512 records for 725 species. NDM/VNDM analyses identified 135 areas of endemism, which were consolidated into 10 generalised areas. These overlapping patterns revealed common areas of endemism, including Central Africa, Western-Central Africa, Western Africa, West Indies, Northern Amazon, Northern Andes, Guiana Shield, Southern Amazon, America Platina and the Southeastern Mountain Range. This study represents the first explicit assessment of endemism patterns in the family using a quantitative methodology and underscores its significance for further research on Gondwanan distribution patterns.