This mud tells a story.
Paleoecology is the textbook.
Sherri's job is to read the story, and to interpret what the diatom and pollen species indicate about the environment. More on Diatoms. This micro-Coliseum is actually a diatom called Paralia sulcata . It lives on the bottom of estuaries and marine environments, and disappears if the water gets too fresh or silty. Achnanthes delicatula is a common brackish water species.