T171 Paleoenvironmental Reconstruction of Hominin Sites: New Methods, New Data, and New Insights II
Monday, 2 November 2015
1:30 PM - 5:30 PM
Room 324
NEW INVESTIGATIONS INTO THE STABLE ISOTOPE ECOLOGY OF THE MAMMAL COMMUNITY FROM ELANDSFONTEIN, SOUTH AFRICA: IMPLICATIONS FOR C4 PLANT DISTRIBUTIONS AND HOMININ PALEOBIOLOGY IN THE CAPE FLORAL REGION DURING THE QUATERNARY
Paper number: T171-10
Program: Technical Sessions
Time: 3:40 PM – 3:55 PM
Authors
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David R. BraunThe George Washington University, Washington, DC
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Sophie B. LehmannJohns Hopkins University, Baltimore, MD
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Thalassa MatthewsIziko Museums of South Africa, Cape Town
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Naomi E. LevinJohns Hopkins University, Baltimore, MD
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Deano StynderUniversity of Cape Town, Cape Town
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Frances ForrestThe Graduate School and University Center/City University of New York, New York, NY
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Laura BishopLiverpool John Moores University, Liverpool
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Robyn PickeringUniversity of Melbourne, Melbourne
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Dave RobertsUniversity of Free State, Bloemfontein
Abstract
The contemporary winter rainfall zone (WRZ) along the west coast of southern Africa is dominated by low-height, shrubby, fire-adapted fynbos vegetation that utilizes the C3 photosynthetic pathway. Although the modern distribution of this vegetation is clearly defined, we understand little about: 1) the spatial or temporal extent of fynbos taxa during the Quaternary, and 2) how this distribution affected the structure and behavior of the fossil mammalian community during this period. Here we present stable isotope data that bear on these questions from the site of Elandsfontein (EFT), a mid-Pleistocene (1.0 – 0.6 Ma) locality found in the WRZ with abundant, in situ fossils and artifacts found in direct association. We find that enamel δ13C values of large herbivores from the site (n=214) suggest minimal C4 vegetation within a C3 dominated system. However, δ13C values of teeth from the mole-rat Bathyergus suillus (n=81) at EFT are significantly higher than those of contemporaneous large herbivores and suggest a significant presence of plants utilizing the C4 photosynthetic pathway. Additionally, we find that artifact density at EFT localities is positively correlated with δ13C values of B. suillus teeth, suggesting that more intense occupation may be associated with greater concentrations of C4 vegetation. Lastly, we hypothesize that the consistent presence of water near springs at EFT may have facilitated conditions in which a significant proportion of C4 vegetation could thrive in a place in which C3 plants otherwise dominate.