Some paleontologists believe that certain species of dinosaurs guarded their young in protective nests long after the young hatched  As evidence, they cite the discovery of fossilized hadrosaur babies and adolescents in carefully designed nests  But similar nests for hatchlings and adolescents are constructed by modern crocodiles, even though crocodiles guard their young only for a very brief time after they hatch
Hence,
it is unclear whether what we learn about hadrosaurs from their fossilized remains tells us anything about other dinosaurs