Stop to think about it. How far do you think an arrow shaft would fly with a two inch plus rock tied on the end? Not very far. "Bird Points" were true arrowheads but were also used as points on darts fired from blow guns. I've got many that are less than 1/4" long. Atlatl points ranged between 1 and 2 inches and were usually quite triangular. They were set into a featherless small diamiter shaft which in turn fitted into a much larger diamiter shaft. That way when a target was struck they could pull the heavy shaft free and reload another smaller shaft. Knives were extremely important and yes, what many think of as arrowheads, are really knives. Also, most tools were multi purpoused like todays Swiss Army Knives. That was to conserve flint and lesson the need for a large number of seperate tools. Knives, scrapers, and drills will often outnumber the amount of true arrowheads you find on a site. Little was thrown away and tools, usualy drills, scrapers, awls and gravers, were made from broken larger pieces. Paleo and Archaic cultures relied heavily on hunting almost exclusively, and the game hunted was much larger, so you'll find more spear points of those time frames. During the Woodland period effort was divided between hunting and gathering of wild food sources. During the Mississipian period, the mound builders, more effort went towards growing crops and ceremonies. Tools reflect the needs of each phase. Actually, the older points tend to be better made because more time and effort went into making them. As man evolved more time went into gathering and growing food as well as ceremonies. That provided less time to spend on making many of the previously needed tools and the quallity reflects it with the exception of the Mississipian period where many stone objects were ceremonial. Often pieces were deliberately broken after use to free the spirit of the stone. When I find a piece I thank the Grandfathers for guiding me to it and I always leave a pinch of tobacco or corn meal in it's place. That is to show both respect and give thanks. As a result I often find pieces, that to me are in plain sight, that others simply don't see. Many times I pick pieces up right at their feet.
"Bird Points", paddle drill & Thunderbird Drill ( made from a broken knife ), ceremonial fish hook
Left to right starting at upper left corner angled facing down are three atlatl points, knife, atlatl point, knife, and two more atlatl points the second from the right being a reworked Adena Dickson knife
Excepeptionaly nice bird point 3,000 years old