The capacity for seed dispersal by two herbivorous turtles, the aquatic Rhinoclemmys funerea and the terrestrial R. annulata, was investigated in the vicinity of Tortuguero, Costa Rica. Defecated seeds of several riparian plant species from R. funerea feces and defecated seeds of several terrestrial plant species, mainly characteristic of treefall areas, from R. annulata feces germinated as well as uningested seeds with which they were compared. The Rhinoclemmys funerea habit of regularly emerging from water to forage and defecate on river banks may contribute to the establishment of riparian species such as Dieffenbachia longispatha and Ficus glabraia. Rhinoclemmys annulata forages through tropical wet forest habitats, spending a disproportionate amount of time feeding in treefall areas. Its movement between these areas and defecation of seeds while foraging in them may contribute to the establishment of the distinctive flora of these small, disjunct habitats.