Bayesian Analysis of Haskett Projectile Point Radiocarbon Dates in the Intermountain West Demonstrates Contemporaneity with Clovis and Folsom Points

Abstract

We evaluate existing radiocarbon dates at sites containing Haskett stemmed projectile points, present 12 new dates from 5 components at 4 sites, and model the age of Haskett points in a multiphase Bayesian framework with trapezium boundaries. We present multiple models with variable prior information to explore the impacts of different interpretations of the archaeological record, and ultimately favor a model where Haskett points appeared between 13,260 and 12,895 calendar years ago and fell out of use between 11,785 and 11,390 calendar years ago, a period of between 1115 and 1555 years. When compared to Bayesian analyses of Clovis and Folsom points, our preferred model suggests Haskett emerged at a similar time as Clovis and lasted longer than both fluted point complexes. Our results also indicate Haskett preceded other unshouldered stemmed point complexes in North America, providing further support for an ancestral-descendant relationship like that proposed for Clovis and Folsom.