Stable isotope evidence for an amphibious phase in early proboscidean evolution.

ABSTRACT: The order Proboscidea includes extant elephants and their extinct relatives and is closely related to the aquatic sirenians (manatees and dugongs) and terrestrial hyracoids (hyraxes). Some analyses of embryological, morphological, and paleontological data suggest that proboscideans and sirenians shared an aquatic or semiaquatic common ancestor, but independent tests of this hypothesis have proven elusive. Here we test the hypothesis of an aquatic ancestry for advanced proboscideans by measuring delta(18)O in tooth enamel of two late Eocene proboscidean genera, Barytherium and Moeritherium, which are sister taxa of Oligocene-to-Recent proboscideans. The combination of low delta(18)O values and low delta(18)O standard deviations in Barytherium and Moeritherium matches the isotopic pattern se

SUBMITTER: Liu AG 

PROVIDER: S-EPMC2311368 | biostudies-literature | 2008 Apr

REPOSITORIES: biostudies-literature