A unique new genus and species of spider beetle from Namaqualand from the Succulent Karoo Biodiversity Hotspot in South Africa is described. The genus Carinomeziumgen. n. is characterized by pronounced longitudinal carinae on the elytra, four large rounded setal tufts that cover the pronotum, and the very small body size. The single representative species, Carinomezium namaquaensissp. n. is diagnosed, described, and illustrated. The phylogenetic placement of this taxon is also discussed.