Yakker, look at the pic on the right, and enlarge it. Notice the bottom edge is chipped the entire length. Then notice here are no other similar edges anywhere. To me, that looks like a worked edge.
I'm agreeing with Quito, that the bottom edge has been worked and I'll bet if you hold the notched area with your thumb and forefinger it could be utilized as a small knife.
"I'm agreeing with Quito, that the bottom edge has been worked and I'll bet if you hold the notched area with your thumb and forefinger it could be utilized as a small knife."
I have proposed this theory to several others before. The notch fits a thumb and finger perfectly for a knife. Others say it's nothing.