This has to be one of my coolest points. I found it today at the end of a long unproductive beach walk. Only found a few flakes, so I decided to head for the truck. We walked back not by the beach but a long driveway and in a spot where someone had done some brush cutting last year and cut too low, this was perched on a little pedestle of dirt. Almost mistook it for a leaf. It's missing the very tip and one wing, also it's almost perfectly flat on the back side. never seen the like here. Thanks for the look
The "flat" spot is simply the ventral surface of the spall they made it from. The Ventral surface of a spall is the flat, inside part closest to the original core, the outside being the Dorsal. "Birdies" (arrow points) are typically made from detaching a spall (flake) from a larger core. That flake is then knapped to a more functional shape. It's very common for them to leave the original surface and not flake to the center if they didn't need to on arrow points. That's a common occurance that you'll notice on alot of points, especially the small arrow points.