The spiny spider crab, Samadinia pulchra (Miers in Tizard, Moseley, Buchanan & Murray, 1885) (type locality: Bohol Sea, Philippines) has long been considered to be widespread in the western Pacific and Indian Ocean, with Anamathia livermorii Wood-Mason in Wood-Mason & Alcock, 1891, described from the Andaman Sea, in its synonymy. Reassessment of Samadinia pulchra from throughout its purported range indicates that it comprises a complex of three species: S. pulchra sensu stricto, occurring in the northwestern Pacific, from the South China Sea to Japan; S. livermorii, occurring in the Indian Ocean, ranging from southwestern Indonesia to East Africa; and a new species, S. jimlowryi sp. nov., ranging from northwestern Australia to southeastern Indonesia.