187 Journal of California and Great Basin Anthropology ฀|฀Vol.฀32,฀No.฀2฀(2012)฀|฀pp.฀187–195 REPORT Primary and Secondary Uses for Ground Stone: A Possible Case of Zostera marina Exploitation on Isla Cedros MIKAEL FAUVELLE Department of Anthropology, University of California, San Diego, La Jolla, CA 92093 LISA MICHELLE SMITH Department of Anthropology, The University of Montana, Missoula, MT 59812-5112 MATTHEW DES LAURIERS Department of Anthropology, California State University, Northridge. Northridge, CA 91330 This report presents data from the macrobotanical analysis of five sites on Isla Cedros, Baja California. Of particular interest is the high proportion of eelgrass (Zostera marina) found in three of the ive soil samples, including one from a non-residential site. Because of this signature, we suggest that prehistoric islanders may have been processing Zostera seeds as a subsistence resource in a similar fashion to the Seri of the Sea of Cortez. Such a scenario would explain the presence of ground stone assemblages on Isla Cedros, despite the island’s lack of economically significant terrestrial seeds or grains. Alternatively, we explore the possibility that the island ground stone industry was focused on the production of ish meal, a storable foodstuff that is speciically mentioned in ethnohistoric accounts of the island. Located off the Paciic Coast of Baja California, midway between San Diego and Cabo San Lucas, Isla Cedros is a rocky and arid island measuring 36 kilometers along its greatest length. First colonized during the Terminal Pleistocene (Des Lauriers 2006, 2008, 2010), by the time of European contact Isla Cedros was home to some of the densest human populations in the Peninsular region (Des Lauriers 2005a, 2009, 2010). A relatively large carrying capacity was possible due to the surprising frequency of potable water sources and was further facilitated by the use of maritime technologies and collection strategies, including the use of seaworthy watercraft (Des Lauriers 2005b). In addition to the ready availability of marine resources, prehistoric Cedros islanders would have been able to exploit numerous terrestrial plant resources, including agave (Agave shawii), barrel cacti (Ferocactus sp.), prickly pear (Opuntia [Platyopuntia] sp.), mormon tea (Ephedra sp.), wolfberry (Lycium sp.), lemonade berry (Rhus integrifolia cedrosensis), and jojoba (Simmondsia sp.). Unlike other coastal groups in both Alta and Baja California, however, Cedros islanders had relatively few edible nut or seed resources. Seeds belonging to the Chenopodiaceae and Amaranthaceae families (bledo), for example, were often consumed on the Baja California mainland and were stored for times of food shortages (Aschmann 1959:64, 77). These seeds are rare on the island, however, and are generally found only in the margins of pine forests and a few spring areas. This relative dearth of edible seeds requires us to question the function of ground stone tools manufactured and used by prehistoric islanders. MACROBOTANICAL ANALYSIS Soil samples from ive sites (PAIC-32, -36, -38, -44, and -47) on Isla Cedros are discussed in this report. The sites range in date from the Terminal Pleistocene/Early Holocene through the Late Holocene (Table 1) and are located throughout the Island (Fig. 1). PAIC-36, -38 and -47 are all large Late Holocene village sites with multiple distinct house features, while PAIC-44 is a Terminal Pleistocene and Early Holocene occupation with evidence of broad spectrum resource exploitation (Des Lauriers 2006). PAIC-32 is a Late Period site with no house features, and may have been a logistical camp associated with PAIC-36. Soil samples from PAIC-32, -36, -38 and -44 were taken from 10 x 10 cm. column samples. All samples were taken from site centers and consist of A-horizon soils mixed with a large amount of