>>539734 There were certain periods in history when life was very abundant. The quick and research free method would be to go to a place where you found a concentration of fossils (like an ancient clam bed, crinoids, just a sea bed) And search along that exposed layer. Stay in the same layer.
And you can google which layers would be richest in life in your area. They'll be sedimentary.
I live in a place where the Interior Sea was for Laurentia so I can find sea fossils from the Jurassic too. I have belemnites and fossilized oysters.
