ABSTRACT
Microwear studies and experimentation were used to analyze fossil Glycymeris gigantea and Dosinia ponderosa shells from the early human occupation of the Covacha Babisuri rock shelter on Baja California's Espíritu Santo Island. The most abundant fossil Glycymeris gigantea shells appear to have been used by early coastal foragers between 11,000 and 8,000 years ago for hide-working. The use of fossil shells as tools that have been dated between 35,000 and more than 47,500 years ago provides a methodological warning to coastal archaeologists concerning the interpretation of the age and contents of early shell middens around the world.
ACKNOWLEDGEMENTS
The project “El Poblamiento de América Visto desde la Isla Espíritu Santo, BCS” was financed by INAH from 2001 to 2008. We thank Takashi Tsutsumi for sending us information about hide-working. Paul Porcasi prepared a coastline map (), Karim Bulhusen Muñóz and Damian Rogel González edited the drawings ( and ). Magdalena de los Ríos provided the calibration dates of the samples shown in . Andrea Guía explained the merits of analyzing the fauna remains by NISP. Jon Erlandson pointed out the possible eccentric crescent from the early levels at Covacha Babisuri and provided editorial comments on earlier versions of this paper. Amira Ainis and Tomas Bowen provided us some useful information. Amy Gusick and Judy Porcasi gave us constructive assistance. Don Laylander helped to revise the draft article. We received valuable suggestions from three anonymous peer reviewers and Torben Rick.