TY - JOUR
T1 - Pedogenic carbonate stable isotopic evidence for wooded habitat preference ofearly Pleistocene tool makers in the Turkana Basin
AU - Quinn, Rhonda L.
AU - Lepre, Christopher
AU - Feibel, Craig S.
AU - Wright, James D.
AU - Mortlock, Richard A.
AU - Harmand, Sonia
AU - Brugal, Jean Philip
AU - Roche, Hélène
N1 - Funding Information:
We thank the office of the President of Kenya and the National Museums of Kenya for permission to conduct this research. TOTAL Kenya, the WTAP team, and Meave and Louise Leakey provided invaluable logistical support. Funding was provided by the French Ministry of Foreign Affairs , the Center for Human Evolutionary Studies (CHES) at Rutgers University , and the National Science Foundation ( BCS 02-18511 to C.S.F.). We thank Jason Lewis of Rutgers University and two anonymous reviewers for editorial comments. The Department of Earth and Planetary Sciences at Rutgers University provided support of the Stable Isotope Laboratory.
PY - 2013/7
Y1 - 2013/7
N2 - The origin and evolution of early Pleistocene hominin lithic technologies in Africa occurred within the context of savanna grassland ecosystems. The Nachukui Formation of the Turkana Basin in northern Kenya, containing Oldowan and Acheulean tool assemblages and fossil evidence for early members of Homo and Paranthropus, provides an extensive spatial and temporal paleosol record of early Pleistocene savanna flora. Here we present new carbon isotopic (δ13CVPDB) values of pedogenic carbonates (68 nodules, 193 analyses) from the Nachukui Formation in order to characterize past vegetation structure and change through time. We compared three members (Kalochoro, Kaitio, and Natoo) at five locations spanning 2.4-1.4Ma and sampled in proximity to hominin archaeological and paleontological sites. Our results indicate diverse habitats showing a mosaic pattern of vegetation cover at each location yet demonstrate grassland expansion through time influenced by paleogeography. Kalochoro floodplains occurred adjacent to large river systems, and paleosols show evidence of C3 woodlands averaging 46-50% woody cover. Kaitio habitats were located along smaller rivers and lake margins. Paleosols yielded evidence for reduced portions of woody vegetation averaging 34-37% woody cover. Natoo environments had the highest percentage of grasslands averaging 21% woody cover near a diminishing Lake Turkana precursor. We also compared paleosol δ13CVPDB values of lithic archaeological sites with paleosol δ13CVPDB values of all environments available to hominins at 2.4-1.4Ma in the Nachukui and Koobi Fora Formations. Grassy environments became more widespread during this interval; woody canopy cover mean percentages steadily decreased by 12%. However, significantly more wooded savanna habitats were present in the vicinity of lithic archaeological sites and did not mirror the basin-wide trend of grassland spread. Hominin lithic archaeological sites consistently demonstrated woody cover circa 40% throughout our study interval and were 4-12% more woody than coeval basin environs. We propose that Turkana Basin early tool makers may have preferred a more wooded portion of the savanna ecosystem to reduce heat stress and to gain differential access to potable water, raw materials, animal carcasses, and edible plants.
AB - The origin and evolution of early Pleistocene hominin lithic technologies in Africa occurred within the context of savanna grassland ecosystems. The Nachukui Formation of the Turkana Basin in northern Kenya, containing Oldowan and Acheulean tool assemblages and fossil evidence for early members of Homo and Paranthropus, provides an extensive spatial and temporal paleosol record of early Pleistocene savanna flora. Here we present new carbon isotopic (δ13CVPDB) values of pedogenic carbonates (68 nodules, 193 analyses) from the Nachukui Formation in order to characterize past vegetation structure and change through time. We compared three members (Kalochoro, Kaitio, and Natoo) at five locations spanning 2.4-1.4Ma and sampled in proximity to hominin archaeological and paleontological sites. Our results indicate diverse habitats showing a mosaic pattern of vegetation cover at each location yet demonstrate grassland expansion through time influenced by paleogeography. Kalochoro floodplains occurred adjacent to large river systems, and paleosols show evidence of C3 woodlands averaging 46-50% woody cover. Kaitio habitats were located along smaller rivers and lake margins. Paleosols yielded evidence for reduced portions of woody vegetation averaging 34-37% woody cover. Natoo environments had the highest percentage of grasslands averaging 21% woody cover near a diminishing Lake Turkana precursor. We also compared paleosol δ13CVPDB values of lithic archaeological sites with paleosol δ13CVPDB values of all environments available to hominins at 2.4-1.4Ma in the Nachukui and Koobi Fora Formations. Grassy environments became more widespread during this interval; woody canopy cover mean percentages steadily decreased by 12%. However, significantly more wooded savanna habitats were present in the vicinity of lithic archaeological sites and did not mirror the basin-wide trend of grassland spread. Hominin lithic archaeological sites consistently demonstrated woody cover circa 40% throughout our study interval and were 4-12% more woody than coeval basin environs. We propose that Turkana Basin early tool makers may have preferred a more wooded portion of the savanna ecosystem to reduce heat stress and to gain differential access to potable water, raw materials, animal carcasses, and edible plants.
KW - Carbon isotopes
KW - Paleolithic archaeological sites
KW - Pleistocene East Africa
KW - Savanna environments
UR - https://www.scopus.com/pages/publications/84879149656
UR - https://www.scopus.com/pages/publications/84879149656#tab=citedBy
U2 - 10.1016/j.jhevol.2013.04.002
DO - 10.1016/j.jhevol.2013.04.002
M3 - Article
C2 - 23726932
AN - SCOPUS:84879149656
SN - 0047-2484
VL - 65
SP - 65
EP - 78
JO - Journal of Human Evolution
JF - Journal of Human Evolution
IS - 1
ER -