Acidic soil will eventually dissolve most remains over the centuries, in those regions that have it, such as here. Cities are built on top of old structures, graves, etcetera over millenia to the point that some very ancient ones appear to have been placed on a hill. You can hardly build anything new in Jerusalem without having graves turn up.
How many wild animals, including large ones, have died on this earth? Most of their remains disappear. The only ones preserved for any length of time were buried in mud or frozen, apparently.
The notion that we’re somehow running out of land is a very urban one. We’re not. Maybe we’re running out of convenient locations for cemeteries in highly populated areas, but we’re certainly not running out of land.
The other interesting belief is that the Earth has not gained or lost any volume since its creation.
e.g. all liquids, gases and solids - all living cells - animal, vegetable & minerals are converted, absorbed, released and refabricated.
Well - I read that somewhere;)
As will alkaline (Lye).