quote:
...in order to fossilize, these organisms had to be burried suddenly and that indicates catastrophy. They don't just lie around for eons on the surface until they fossilize. On the surface it doesn't take long for them to decay.
Indeed, fossils have a tough time being preserved on land surfaces, but... What we are talking about are marine fossils - The animal lived beneath the sea.
The material remains of the creature is probably Calcium Carbonate. This material will not decompose (rot) by (general) biological processes. It can be destroyed by 1) Solution - but they are in a carbonate saturated environment, or 2) Physical distruction (crushing, abrasion, etc.) I put the "general" above, because this physical discruction can have a biological component. But essentially, a shell is just another piece of limestone.
Catastropic processes are not required for preservation. Indeed, a limestone deposit is very much an indicator of a quiet marine environment - there is little non-carbonate detritus being introduced.
Moose