Maybe medieval people happened upon a T-Rex fossil and came to a relatively logical conclusion that dragons existed.

I’ve read a couple books on this actually, thats exactly what happened. Also cyclops are from looking at bones from a certain type of baby elephant. The giant note hole and tiny eyes made it look like a single eye.

Yep, can confirm! And what’s even funnier to me is that back in the dark ages, Greek people used to find a lot of prehistoric bear skeletons - and those look exactly like human skeletons, except they’re like eight feet tall or something - so they naturally assumed those were the heroes of legend, and made armour and clothes for them and reburied them with the most splendid and sacred religious ceremonies they could think of? Fast forward five centuries, Athens’ all modern and rational, philosophers and scientists aren’t taking any shit from anyone - but the problem is, people will randomly find graves containing giant-ass warriors, so that’s something that can’t be explained away and yeah, demigods were a thing and yeah, they used to be eight feet tall and sorry I don’t make the rules.

I never thought of this before!

… but who says we know how dinosaurs looked like? they might’ve all just been giant chicken.