It is often assumed that only plants with a fleshy fruit disperse inside vertebrate guts, i.e. by "endozoochory". However, only 8% of European angiosperms have a fleshy fruit, and endozoochory of other plants by herbivorous or granivorous birds and mammals is widespread in nature. Many terrestrial and aquatic plants disperse via endozoochory by migratory waterbirds, providing long-dispersal dispersal. But how do they survive gut passage? Is the mechanical resistance to digestion different to that recorded in fleshy-fruited plants? Using SEM and 11 plants we compared seed morphology before and after gut passage through mallards. Diverse seed and dry fruit architecture provided multiple mechanisms to resist digestion and so enable seed survival. There are no fundamental differences in the way that these seeds, or those from fleshy-fruited plants, survive gut passage. Both plant types are pre-adapted for endozoochory and for seed dispersal mutualisms. informacion[at]ebd.csic.es: Costea et al (2019) The Effect of Gut Passage by Waterbirds on the Seed Coat and Pericarp of Diaspores Lacking "External Flesh": Evidence for Widespread Adaptation to Endozoochory in Angiosperms. PLoS ONE 14(12): e0226551