Fig. 1: KNM-ER 101000 locality, geostratigraphy and specimen distribution map.

a, Satellite map of the Turkana Basin region indicating the geospatial location of the KNM-ER 101000 excavation site. b, Stratigraphical section of the lake margin facies, including the interval from which the KNM-ER 101000 fossils derive. Fine sands with abundant nondecalcified molluscs, silts with saline crusts (halite) and clays with multiple pedogenic carbonate (Bk) horizons characterize this interval of strata. Note that the source strata for KNM-ER 101000 are 10–25 cm above a siltstone layer that has a known hominin trackway surface (FE22)¹⁵. c, Specimen distribution map of the KNM-ER 101000 excavation. Each grid square represents 1 × 1 metre. Numbers in parentheses refer to the specimen numbers in Supplementary Table 1. Specimens not listed on the map were recovered from sieving fragments from the mapped area after excavation. d, Image of the outcrop of the excavation site of KNM-ER 101000. The photograph was taken from the top of the hill looking down on the site, facing south. Base map in a from Google Earth (Google, Landsat/Copernicus, Data SIO, NOAA, US Navy, NGA, GEBCO). Diagram in b adapted with permission from ref. ¹⁵, AAAS.