<p>Barrier islands, often unnoticed in biodiversity conservation, play a critical ecological role as dynamic coastal ecosystems that protect mainland habitats from storm surges, support unique biotic communities, and serve as vital nodes for nutrient cycling. In this context, the Vypin-Kadamakkudy Barrier Island System (VKBIS) in Kerala, India, is considered for documenting one of the diverse coleopterans coming under the subfamily Scarabaeinae. It is the first systematic study on dung beetles from a tropical barrier island globally, the initial documentation of insular dung beetles in Kerala, and the first-ever study on the Scarabaeinae subfamily in VKBIS. The study analysed the diversity, nesting guild composition, and temporal patterns of dung beetles of the selected barrier island system. It unravels the selected barrier island system, an urbanising, open ecosystem, for its capacity to maintain a comparatively diverse dung beetle assemblage. Dung beetles preferred the dry season for its abundance and active dispersal. The study documented tunnelers and dwellers with the complete absence of rollers from VKBIS. Increased nighttime foraging by the dung beetles was also observed in the study area, irrespective of the season. VKBIS was also observed with seasonal shifts in diel preferences by the members of the taxon. Hopefully, the study will be an asset as a stepping stone for future studies on dung beetles of barrier island systems across the globe.</p>