We also found all these prehistoric stingray teeth.
I didn't know rays had teeth until that day on the banks of the Potomac. I didn't believe the boys when they claimed to have found ray teeth. So I Googled it right there and found out they were right. If you still don't believe that rays have teeth, I know an eleven- and eight-year old who would be willing to convince you.
Anyway, I got crafty with the teeth and made two shadowbox displays for them.
I used 60-weight sandpaper as a background and, with much finger-cramping and eye-squinting, glued the individual teeth to the background.
There is one display for each boy but of course the ongoing argument has started about who gets which display, "cuz this one has the biggest shark tooth...." Maybe by the time they have walls of their own to hang them on, they will not care about the size of the teeth. I can hope.