Polydactyly in the prehistoric American Southwest

General surveys of skeletal collections from Arizona for evidence of trauma and pathology led to the identification of polydactyly in two subadults. Polydactyly is a congenital condition characterised by the presence of extra digits on the hands or feet. Both affected subadults exhibit a sixth digit in the form of a branching fifth metatarsal. One of the affected individuals is an infant from the Tapia del Cerrito site exhibiting Y-shaped fifth metatarsals indicative of postaxial type A polydactyly. The second individual is a juvenile from the Nuvakwewtaqa (Chavez Pass Ruin) site exhibiting a left fifth metatarsal with a lateral branch, also diagnosed as postaxial type A polydactyly. These two cases appear to be the first examples of polydactyly from archaeological contexts identified among subadults, and bring the total number of known cases from the American Southwest to six. Discovery of so many examples of this relatively rare condition amongst the Puebloan people of the Southwest adds to the evidence that, rather than simply being an artistic motif, rock art depictions featuring hands and feet with six digits were probably inspired by observation of the condition amongst living people. Furthermore, burial treatment of the Tapia del Cerrito infant suggests that polydactyly may have conferred a special status on the bearer. Copyright © 2006 John Wiley & Sons, Ltd.