1. Archaeologists collectively refer to spear points, dart points and arrowheads as "projectile points." Spears are propelled by the arm without the aid of any other device, and spears need to be heavy to penetrate deeply. Darts are smaller than spears and are propelled by an "atlatl" which is a stick held in the hand with a hook on the end that seats into a socket in the butt of the dart. The atlatl adds considerable leverage propelling the dart several times faster than can be thrown by arm alone, and its penetration is as much a product of its high velocity as its mass. Arrows are propelled by bows and they travel considerably faster than is possible for either darts or spears, and it is their velocity, not their mass, which produces deep penetration. In this guide, points are divided into two categories: small and large. Small points are arrow points and large points are dart and spear points.
  2. This approach of measuring the Shoulder Angle from a horizontal line follows Thomas 1981. This is probably the best way to measure the Shoulder Angle to avoid positive and negative angles, as well as angles that exceed 360º.
  3. Points with Blade Widths close to 16.5 mm might be misclassified. Although very rare, Northern Side-notched points were made unusually small (e.g., Northern Side-notch photo g) or have been resharpened enough to reduce their blade widths sufficiently to measure within the upper range of Desert Side-notched points. Also rare, Small Notched points of various types do exceed the 16.5 mm threshold. However, this applies to only four points out of over 400 notched points (less than 1%) in the Eastern Idaho Database.
All content Copyright © 2009 by Richard N. Holmer
Informatics Research Institute