As for birds being dinosaurs, you also have a lot of physical similarities too! The feet of non-avian dinosaurs are similar to those of modern birds with hollow bones, and I think the skulls were similar in shape too. Recently, we have also found evidence of some dinosaurs being feathered. There is also evidence of bird-like behaviours in some dinosaurs, like brooding (e.g. a hen sitting on some eggs) and herding (grouping together)