there are several lines of neobatrachia which have evolved into tree frogs. these groups are only distantly related, but they have evolved for a long time in similar conditions. the result is that now there are species from different groups which look very much like each other. this is convergent evolution. it goes so far that in almost all cases, where one group occurs, another does not. their current distribution shows that the last common ancestor of the groups lived before the dinosaurs disappeared.