title: Stable isotope-based diet reconstructions of Turkana Basin hominins.
abstract: Hominin fossil evidence in the Turkana Basin in Kenya from ca. 4.1 to 1.4 Ma samples two archaic early hominin genera and records some of the early evolutionary history of Paranthropus and Homo. Stable carbon isotopes in fossil tooth enamel are used to estimate the fraction of diet derived from C3 or C4 resources in these hominin taxa. The earliest hominin species in the Turkana Basin, Australopithecus anamensis, derived nearly all of its diet from C3 resources. Subsequently, by ca. 3.3 Ma, the later Kenyanthropus platyops had a very wide dietary range--from virtually a purely C3 resource-based diet to one dominated by C4 resources. By ca. 2 Ma, hominins in the Turkana Basin had split into two distinct groups: specimens attributable to the genus Homo provide evidence for a diet with a ca. 65/35 ratio of C3- to C4-based resources, whereas P. boisei had a higher fraction of C4-based diet (ca. 25/75 ratio). Homo sp. increased the fraction of C4-based resources in the diet through ca. 1.5 Ma, whereas P. boisei maintained its high dependency on C4-derived resources.
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA. thure.cerling@utah.edu
authors.forename: Thure E
authors.initials: TE
authors.lastname: Cerling
authors.forename: Fredrick Kyalo
authors.initials: FK
authors.lastname: Manthi
authors.forename: Emma N
authors.initials: EN
authors.lastname: Mbua
authors.forename: Louise N
authors.initials: LN
authors.lastname: Leakey
authors.forename: Meave G
authors.initials: MG
authors.lastname: Leakey
authors.forename: Richard E
authors.initials: RE
authors.lastname: Leakey
authors.forename: Francis H
authors.initials: FH
authors.lastname: Brown
authors.forename: Frederick E
authors.initials: FE
authors.lastname: Grine
authors.forename: John A
authors.initials: JA
authors.lastname: Hart
authors.forename: Prince
authors.initials: P
authors.lastname: Kaleme
authors.forename: Hélène
authors.initials: H
authors.lastname: Roche
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Uno
authors.forename: Bernard A
authors.initials: BA
authors.lastname: Wood
mesh_terms: D000818:Animals; D002247:Carbon Isotopes; D003743:Dental Enamel / Q000737:chemistry; D004032:Diet / Q000266:history*; D005580:Fossils; D049690:History, Ancient; D015186:Hominidae; D006801:Humans; D007630:Kenya
chemical_list: D002247:Carbon Isotopes
keywords: Theropithecus; hominid