Professional shyster making something like the Georgia guides tones or golden tablets to "discover" and then use as the basis of a religion, is the first thing that comes to mind.
Oh, you mean dinosaurs! There's basically never been a full one found. The closest one ever was found under dubious circumstances. The process for extracting them is to make tiny chips in rock and casts as you go along pretty much allowing you to shape as desired. The sites are of course highly guarded. Of course the most complete was the ever popular TRex.
Dinosaur paleontology is a religious racket. Sure there was lots of megafauna and their were some large flightless birds with various levels of feathering. Like anything though money corrupts and the money behind dinosaurs is huge. Every kid has toys, books, theres movies, TV shows, museums, etc.
They're not carving stone when digging out the fossils. And the average fossil digger is not Michaelangelo or capable of sculpting a negative dinosaur skeleton out of solid rock. Just imagine hundreds of people on a dig trying to get the symmetry and proportions right. The answer is that the material inside the impression left by the decaying bones is softer than the rock it's encased in.
Sure, dinos for kids are big money, but there's just a massive amount of proof they existed. The fact that an industry exists monetizing a natural phenomenon doesn't automatically mean the phenomenon doesn't exist. That's the "anything mainstream must be fake" conspiracy theory. Some mainstream things are real. What proof is there for the world being created in seven days besides a single book of stories invented a couple thousand years ago? And by the way, don't parents buy their kids a lot of religious things... way more than dinosaur dolls?
[edit] if I'm just missing the sarcasm here, sorry, it's been a long day.
This is obviously not intended as an informational post or as one that would be likely to be taken as fact by most people. You'll never be able to recover the time you spent typing all that.