Why did dinosaurs become extinct?
This Australian cassowary certainly looks half-dinosaur.
All dinosaurs didn't become extinct because modern birds are, in fact, dinosaurs. There are scientists in our Ornithology Department who are investigating the 15,000 species of birds alive today. That's 15,000 different kinds of living dinosaurs! So get some binoculars and go dinosaur watching. Now, let's talk about why the non-bird dinosaurs became extinct about 65 million years ago. The answer iswe don't know. That question is unanswerable based on the fossil record. I have no doubt a big meteorite hit Earth about 65 million years ago, but we have no evidence that this caused the great dinosaur extinction.