Dinosaurs walked the Earth millions of years ago, but when a massive asteroid smacked into our planet, it wiped them all out. Fast-forward to now, and humans un-Earth fossils that tell us seemingly endless stories about these gigantic animals.
A fossil is fundamentally just a carbon copy of a dinosaur's bone structure, but in limited cases, we can also get a glimpse of a dinosaur's skin or other exterior features. It's from these fortunate circumstances that we've ascertained what kind of skin dinosaurs had and whether some exhibited feathers or scales.
Although many dinosaurs may not have looked precisely the way they do in Jurassic Park, that's not to say everything depicted in Hollywood is far from the truth. It's challenging to say for sure exactly what a dinosaur may have looked like, but fossils can give us a pretty good idea of their diet, posture, and size.
Determining what dinosaurs existed millions of years ago requires tons of guess-work and a well-established fossil database, but discoveries make the news every day. It's always fun to learn about the next major break that re-writes history and our understanding of what dinosaurs looked like.