One reason projectile points stand out among stone tools is because they are very stylized to show clear differences between their makers, who lived in different times and places. Projectile points are thus an indicator of social variability and tradition; in the puna where mobility of groups was limited, style became localized within small groups. At times styles also may converge, showing cultures influencing each other, or the movement of people over the landscape.
There are many styles of projectile points. The earliest known points from the puna have a triangular shape with a concave base, and are generally very thin. A general trend from early to later times shows points changing from shouldered, to leaf-shaped, to smaller, less elongate points. Some believe that points from the same time should be essentially identical, but there is evidence that there may have been notably different forms between small local groups in the same period during the Preceramic Period of the Junin puna.
Special characteristics seen on some types of projectile points can also be used to classify them. The second picture shows needle point tips from Panalauca, easily identified by the small, finely worked point. Other classes include willows, as seen in the last picture from Pachamachay. Specific characteristics like these are what have been used to group projectile points for archaeological classification.