"In comparing the hadrosaurs with other dinosaurian herbivores, it is striking that they alone lack any obvious defensive or protective adaptations. They possessed no horns, no claws, no sharp teeth, they carried no clubbed or spiked tail, and they had no bony armor. They certainly were not constructed for rapid flight and they cannot be considered giants for their time. In short, the hadrosaurs appear to have been quite defenseless — a most improbable plight. As an alternative it seems increasingly probable that they depended upon the relative security of lakes, swamps, or rivers and thereby escaped from their enemies."