TY  - JOUR
A1  - Wichura, Henry
A1  - Jacobs, Louis L.
A1  - Lin, Andrew
A1  - Polcyn, Michael J.
A1  - Manthi, Fredrick K.
A1  - Winkler, Dale A.
A1  - Strecker, Manfred
A1  - Clemens, Matthew
T1  - A 17-My-old whale constrains onset of uplift and climate change in east Africa
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - Timing and magnitude of surface uplift are key to understanding the impact of crustal deformation and topographic growth on atmospheric circulation, environmental conditions, and surface processes. Uplift of the East African Plateau is linked to mantle processes, but paleoaltimetry data are too scarce to constrain plateau evolution and subsequent vertical motions associated with rifting. Here, we assess the paleotopographic implications of a beaked whale fossil (Ziphiidae) from the Turkana region of Kenya found 740 km inland from the present-day coastline of the Indian Ocean at an elevation of 620 m. The specimen is similar to 17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern straptoothed whales (Mesoplodon). The whale traveled from the Indian Ocean inland along an eastward-directed drainage system controlled by the Cretaceous Anza Graben and was stranded slightly above sea level. Surface uplift from near sea level coincides with paleoclimatic change from a humid environment to highly variable and much drier conditions, which altered biotic communities and drove evolution in east Africa, including that of primates.
KW  - east Africa
KW  - Ziphiidae
KW  - uplift
KW  - drainage
KW  - paleoenvironment
Y1  - 2015
U6  - https://doi.org/10.1073/pnas.1421502112
SN  - 0027-8424
VL  - 112
IS  - 13
SP  - 3910
EP  - 3915
PB  - National Acad. of Sciences
CY  - Washington
ER  -