How is it that some dinosaur bones don’t decompose after millions of years? What keeps them so well preserved compared to the remains of dead animals normally?

Question

How is it that some dinosaur bones don’t decompose after millions of years? What keeps them so well preserved compared to the remains of dead animals normally?

In: 4

Answer 1

Things that get fossilized got buried really quickly after they died. This means that they’re less exposed to the elements and anything that wants to eat them doesn’t have oxygen with which to fuel it (this is the same reason we air seal food in the fridge to keep it more fresh). The overwhelming majority of remains, even those that do get buried relatively quickly, don’t survive for millions of years, though. Fossils are exceptional.