www.sciencemag.org/content/344/6185/750/suppl/DC1 Supplementary Materials for Late Pleistocene Human Skeleton and mtDNA Link Paleoamericans and Modern Native Americans James C. Chatters,* Douglas J. Kennett, Yemane Asmerom, Brian M. Kemp, Victor Polyak, Alberto Nava Blank, Patricia A. Beddows, Eduard Reinhardt, Joaquin Arroyo- Cabrales, Deborah A. Bolnick, Ripan S. Malhi, Brendan J. Culleton, Pilar Luna Erreguerena, Dominique Rissolo, Shanti Morell-Hart, Thomas W. Stafford Jr. *Corresponding author. E-mail:
[email protected] Published 16 May 2014, Science 344, 750 (2014) DOI: 10.1126/science.1252619 This PDF file includes: Materials and Methods Figs. S1 to S13 Tables S1 to S5 Additional Acknowledgements References (26–107) MATERIALS AND METHODS The Hoyo Negro Site and its Regional Context Site description Hoyo Negro (HN) is a large, submerged, underground chamber of Outland Cave, located 20 km N of Tulum, Quintana Roo, Mexico (Fig. S1). It was discovered in 2007 during an exploration of the Outland Cave by Alejandro Alvarez, Alberto Nava Blank, and Franco Attolini of the Proyecto Espeleológico de Tulum (26-27). HN is a bell-shaped chamber (the pit) located below the confluence of three horizontal passages with floors at ~12 mbsl (Fig. 1). The pit is 37 m in diameter at its rim, expanding to 62 m at the boulder-strewn floor, which slopes from 33 mbsl on the north to ~48 m along the south wall. This geometry made it an inescapable natural trap (Fig. S2). HN contains layered fresh and saltwater, with the halocline lying at 15 to 22 mbsl. The freshwater lens is slightly acidic (pH 6.8) and cool (25.2°C), the saltwater is over 95% marine salinity, slightly basic (pH 7.1), and slightly warmer (25.5°C).