A fossil is a fossil is a fossil.

This is another problem coming from the fact that words can be more precise
than nature is. In nature, there is a continuum between the shells of
living mollusks and fossil shells, punctuated only by death. Asking when a
shell becomes fossil is like asking, "Where does blue stop and green
begin?"

So we have "working definitions" of slippery words. Sometimes we use
specialized definitions when they are needed for particular work, like Dr.
Cadee's work on taphonomy (the process of fossilization). David Campbell
and others presented definitions that are of more general use. But I have
to warn you that this is yet another topic on which it's best to "agree to
disagree"...

Andrew K. Rindsberg
Geological Survey of Alabama