On 09/07/2013 09:11, 'Mike' wrote:

..when everything else rots down in a compost heap, don't bones? When a
body vanishes over time in the ground, the bones remain.

They do eventually although how quickly depends on the conditions. A
neighbour is a mycologist and turns up with exciting finds of obscure
fungi growing on rams horns and bones from time to time. They do rot
away eventually - just a lot more slowly than grass clippings and flesh.
Mostly the calcium phosphate remains and if it gets mineralised by
groundwater faster than it erodes then it becomes a fossil.

Kept totally dry, frozen or saturated and/or oxygen free the entire
corpse can be preserved for many centuries in deserts, glaciers and bogs
respectively (or combinations thereof like Arctic tundra).

Just a thought

Mike

--
Regards,
Martin Brown