Ancient DNA Analysis and Stable Isotope Ecology of Sea Turtles (Cheloniidae) from the Gold Rush-era (1850s) Eastern Pacific Ocean

Historical and archaeological evidence documents the importation of sea turtles from the eastern Pacific Ocean (Baja California) to California during the Gold Rush (1848–1855) and through the end of 19th century, but it is unknown whether these 19th century sea turtles foraged in similar ways to their modern counterparts. To identify the species of two Gold Rush-era sea turtle specimens recovered from archaeological deposits in San Francisco, California, we first analyze ancient DNA (aDNA). We then analyze carbon (δ13Ccol), nitrogen (δ15N), and hydrogen (δD) stable isotopes of bone collagen and carbon (δ13Cap) and oxygen (δ18Oap) stable isotopes of bone apatite to test if eastern Pacific sea turtle diets have changed over the past 160 years. Ancient DNA confirms that both archaeological specimens are green sea turtles (Chelonia mydas). The stable isotope values from the 19th-century specimens are statistically indistinguishable from the modern comparatives in both δ13Ccoland δ15N, suggesting that green sea turtle dietary intake has remained relatively unchanged since the 1850s. However, the values are unclear for δD and δ18Oapand require additional research.Support for this work came the University of Oklahoma Libraries Open Access Fund.YesOpen Quaternary is an international peer-reviewed venue for contributions that consider the changing environment of the Quaternary, as well as the development of humanity

Two Biface Clusters and Their Relation to Mortuary Practices in the San Francisco Bay Area

Discrete assemblages, or clusters, of bifaces in mortuary association are a relatively rare phenomenon throughout the greater San Francisco Bay area (cf. Contreras 1957; Wiberg 1988:23). This paper presents a formal description, trace element analysis, and interpretation of two such clusters found close together in a prehistoric cemetery in Santa Clara County, some 30 km. south of San Francisco Bay (Fig. 1)

Historic and modern eastern Pacific green sea turtle stable isotopes

Stable isotope data, specimen photographs and R script for the Gold Rush-era sea turtle specimens from San Francisco, California. The stable isotope data are saved as .csv files. R script is provided as a zip file (OQ_SeaTurtle-master.zip) created from the repository developed and hosted at https://github.com/cylerc/OQ_SeaTurtle. Note: Some stable isotope data provided during analyses are from previously published sources (see .csv files and manuscript for references). This repository dataset is described in the manuscript: Conrad, C., L. Pagès Barceló, J.A. Seminoff, C.N. Turner Tomaszewicz, M.J. Labonte, B.M. Kemp, E.L. Jones, M. Stoyka, K. Bruner and A.G. Pastron. in press. Ancient DNA Analysis and Stable Isotope Ecology of Sea Turtles (Cheloniidae) from the Gold Rush-era (1850s) Eastern Pacific Ocean. Open Quaternary. https://www.openquaternary.com/articles/10.5334/oq.41