Heteromastus namhaensis sp. nov. A abdominal hooded hook in lateral view B posterior end in dorsal view (holotype, NA00155558). Heteromastus gusipoensis sp. nov. C abdominal hooded hook in frontal view D posterior end in dorsal view (holotype, NA00155561). Heteromastus koreanus sp. nov. E abdominal hooded hook in frontal view F posterior end in dorsal view (holotype, NA00155565). Abbreviations: ac, anal cirrus; mf, main fang; neu, neuropod; no, notopod; pyg, pygidium.