| Autor: |
Quinn RL; Department of Sociology, Anthropology, Social Work and Criminal Justice, Seton Hall University, 400 South Orange Ave, South Orange, NJ, 07079, USA. rhonda.quinn@shu.edu.; Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ, 08854, USA. rhonda.quinn@shu.edu., Lepre CJ; Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ, 08854, USA. |
| Abstrakt: |
The extinction of the Paranthropus boisei estimated to just before 1 Ma occurred when C 4 grasslands dominated landscapes of the Eastern African Rift System (EARS). P. boisei has been characterized as an herbivorous C 4 specialist, and paradoxically, its demise coincided with habitats favorable to its dietary ecology. Here we report new pedogenic carbonate stable carbon (δ 13 C PC ) and oxygen (δ 18 O PC ) values (nodules = 53, analyses = 95) from an under-sampled interval (1.4-0.7 Ma) in the Turkana Basin (Kenya), one of the most fossiliferous locales of P. boisei. We combined our new results with published δ 13 C PC values from the EARS dated to 3-0 Ma, conducted time-series analysis of woody cover (ƒ WC ), and compared the EARS ƒ WC trends to regional and global paleo-environmental and -climatic datasets. Our results demonstrate that the long-term rise of C 4 grasslands was punctuated by a transient but significant increase in C 3 vegetation and warmer temperatures, coincident with the Mid-Pleistocene Transition (1.3-0.7 Ma) and implicating a short-term rise in pCO 2 . The contraction of C 4 grasslands escalated dietary competition amongst the abundant C 4 -feeders, likely influencing P. boisei's demise. |
