Looking for a Match

This is my “little” finger on my left hand. There is no bone joint to match the extra crease (most people have 3). I don’t go around gabbing people’s hands, but I’ve never met anyone with an extra crease. Someone told me to check with a gorilla, but I don’t know one to ask. If I find someone with a match, maybe they will know why. Maybe a closed fist in the womb?