Extended Data Fig. 1: Geographic and stratigraphic context of the FLK T69 Complex site.
From: Systematic bone tool production at 1.5 million years ago
a, Location of Olduvai Gorge in Tanzania. b, Main geographical features of the Olduvai Basin. The geographical image was adapted from NASA (https://lpdaac.usgs.gov/products/astgtmv003/), USGS. c, Position of the T69 Complex in the Main Gorge at Olduvai. The geographical image was adapted with permission from ref. 98, Elsevier. d, Stratigraphic position of the bone tool level shown on a composite section of the deepest part of trench T69 and the central area of the T69-T79 west section. e, Position of the T69 Complex within the general chrono-stratigraphic sequence of Bed II in the FLK area. Dates by35,48,52,53. f, Normal (left) and polarized (right) thin section photographs of the sandstone containing the bone tool horizon.
