"Megapaloelodus", on the other hand, seems to have been evolved into a true wading bird, convergent with the true flamingos.Its "knee" (actually ankle) joints had evolved to a peculiar form not known from modern flamingos and only incipient in "Palaelodus"; the function of this character is not known but possibly it enabled the bird to "lock" its leg in standing position when asleep in shallow water, out of the reach of most terrestrial as well as aquatic predators.