Vesicles are produced primarily in the membrane systems of the plasma membrane, endoplasmic reticulum and Golgi apparatus, they move throughout the cell along cytoplasmic filaments to discharge their contents to other organelles or outside the cell.
I don't know if this helps or not but you would want to know the age of the rock (absolute dating) and from there you will be able to know the age of the fossil and what caused it to die.
