Thread: How did scientists come to the conclusion that dinosaurs went extinct?

Now obviously we don't see giant t-rexs and rapters running around outside and all but I was wondering since I've been watching things on discovery about how birds are evolutions of dinosaurs and so are crocodiles and alligators that how do we know that they didn't go extinct they just evolved? did scientists find any significant evidence pointing to their mass extinction? If so than that explains it but why did they come to this conclusion? Thank you for all of the answers^^

you could say they are not all dead except there were certain thing that dinosaurs had but birds and other reptiles don't have

Crocodiles and alligators are not descendant and evolution of dinosaurs; in fact there were crocodilians existing alongside dinosaurs (and crocodilians are a bit more primitive, with their legs on the side rather than under, which is not the best for living on dry land).
And birds are evolution of *some* dinosaurs, the same way we are evolution of some ape-like proto-human that lived a couple of million years ago.

Dinosaurs were reptiles with their legs under the body, there are no such creature alive today, and no descendant except for the birds.