Which Ice Age?

When we say "ice age" we usually mean the one that ended about 10,000 years ago. In the popular science narrative (SciPop) this was the last of several retreats and advances of polar ice over the last 10,000-40,000 years.

Sharks and Bony Fish

Sedimentary deposits containing sharks and bony fish can be assigned to the Mississippian because of how the evolution narrative, of development from primitive to advanced, overlays with the geological timescale.