Discoveries of the rare sweetwater‐crabPlatychirograpsus typicusare hitherto known from Tabasco and Veracruz (Mexico). A new male specimen was found at the Rio de Alatorre. The crab lived under a stone in a quiet area of the river. The cave where the crab dwelled was closed and defended by its mighty pair of scissors. Footprints prove thatPlatychirograpsus typicusdoes not move far away from its living place.