A 17-My-old whale constrains onset of uplift and climate change in east Africa.

Bibliographic Collection: 
Publication Type: Journal Article
Authors: Wichura, Henry; Jacobs, Louis L; Lin, Andrew; Polcyn, Michael J; Manthi, Fredrick K; Winkler, Dale A; Strecker, Manfred R; Clemens, Matthew
Year of Publication: 2015
Journal: Proc Natl Acad Sci U S A
Volume: 112
Issue: 13
Pagination: 3910-5
Date Published: 2015 Mar 31
Publication Language: eng
ISSN: 1091-6490
Keywords: Africa, Animal Migration, Animals, Biological Evolution, Climate Change, Fossils, Geography, Phylogeny, Tomography, X-Ray Computed, Whales

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 ∼ 17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern strap-toothed 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.

DOI: 10.1073/pnas.1421502112
Alternate Journal: Proc. Natl. Acad. Sci. U.S.A.