Discriminating Paleoindian point types from Florida using landmark geometric morphometrics

Traditional artifact typologies are typically poorly defined. While several attributes usually help define a “type,” shape is invariably the most important. Here I report on a study that uses landmark-based geometric morphometrics to better define three Paleoindian point types from Florida: Suwannees, Simpsons, and Transitional Side Notched. Bilaterally symmetric specimens were created from the original artifacts to capture the presumed ideational forms of the points. The shapes of the bases and the entire points were tested to determine whether the types could be discriminated, and if so which shape was best at discriminating the types. The results show that the base configurations were best at discriminating the groups in two different jackknife allocation tests. The entire point shape was less robust due to the variability in blade shape. The study demonstrates that the three point types can be rigorously defined in ways that are usable in daily archaeological practice, and that base shape, rather than the entire shape, is a better discriminator. Further, the study demonstrates the utility of using several freeware programs for processing and analyzing shape data.

► Landmark geometric morphometrics can produce better artifact typologies.
► Bilaterally-symmetric artifacts can better capture the ideational form.
► Bootstrapping methods with replacement better measure the effectiveness of a typology.
► The base of a point better discriminates among groups in a typology.