New hominin remains and revised context from the earliest Homo erectus locality in East Turkana, Kenya

Ashley S Hammond,Sharon Kuo,Maryse Biernat,David B Patterson,Sahleselasie Melaku,Kevin T Uno,Sylvia N Wemanya,David R Braun,Dan V Palcu,Silindokuhle S Mavuso,Emmanuel K Ndiema,Zubair Jinnah

doi:10.1038/s41467-021-22208-x

Abstract

The KNM-ER 2598 occipital is among the oldest fossils attributed to Homo erectus but questions have been raised about whether it may derive from a younger horizon. Here we report on efforts to relocate the KNM-ER 2598 locality and investigate its paleontological and geological context. Although located in a different East Turkana collection area (Area 13) than initially reported, the locality is stratigraphically positioned below the KBS Tuff and the outcrops show no evidence of deflation of a younger unit, supporting an age of >1.855 Ma. Newly recovered faunal material consists primarily of C4 grazers, further confirmed by enamel isotope data. A hominin proximal 3rd metatarsal and partial ilium were discovered <50 m from the reconstructed location where KNM-ER 2598 was originally found but these cannot be associated directly with the occipital. The postcrania are consistent with fossil Homo and may represent the earliest postcrania attributable to Homo erectus.

Highlights

The KNM-ER 2598 occipital is among the oldest fossils attributed to Homo erectus but questions have been raised about whether it may derive from a younger horizon
The Dmanisi hominin fossils may be as old as 1.78 Ma11, and occupation of the site appears to extend to 1.85 Ma11
The Dmanisi dates, which approach the dates for the African H. erectus specimens, raise the possibility that Homo erectus origins could have occurred in Eurasia rather than on the African continent[4]

Summary

Introduction

The KNM-ER 2598 occipital is among the oldest fossils attributed to Homo erectus but questions have been raised about whether it may derive from a younger horizon. KNM-ER 2598 is a thick hominin cranial fragment preserving much of the central occipital bone, including portions of the lambdoidal suture and a distinctive Homo erectus-like occipital torus (Fig. 1)[6]. This fossil was collected from the outcrop surface in 1974 and was initially reported as originating from approximately the level of the KBS Tuff in East Turkana collection Area 156. The most recent Geomagnetic Polarity Time Scale (GPTS 2020) associate the C2r.1r chron to the 1.934–2.120 Ma time interval[9,10] Both DNH 134 and KNM-ER 2598 are critically important fossils because they are slightly older than those recovered from Dmanisi in the Republic of Georgia. The Dmanisi dates, which approach the dates for the African H. erectus specimens, raise the possibility that Homo erectus origins could have occurred in Eurasia rather than on the African continent[4]

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Conclusion