Feeding Ecology and Niche Partitioning of the Laetoli Ungulate Faunas

摘要: The Pliocene ungulate fauna from the ­hominid-bearing Laetolil succession (Southern Serengeti, Tanzania) is investigated with regard to dietary adaptation, niche segregation and change over time. fossiliferous Upper Beds (ULB) (3.63–3.85 Ma) are unconformably overlain by Ndolanya (UNB) (2.66 Ma). Both stratigraphic units contain a rich mammalian fauna, ungulates predominating. Analysis of dental mesowear applied 23 taxa both units, including Equidae, Bovidae Giraffidae, results compared extant species. equids at Laetoli represent only specialized grazers throughout succession. All Alcelaphini Hippotragini have signatures that indicate intermediate feeding strategies, different their modern counterparts mostly grazers. This indicates shift in these lineages, finding also supported isotope studies. Mesowear data ULB suggest representing closely related lineages same genus or even tribe may not serve as actualistic model faunal reconstructions using taxonomic uniformitarianism. three species giraffids remaining bovid were either browsers feeders, but almost complete absence grazing guilds, heavy reliance on browse most fossil herbivores, do support inference environment was dominated grassland. Within it appears fundamental niches converged time, increasingly engaged less abrasive components intermediate-feeders closing gap exploiting more niches. Niche partitioning reflect environmental evolutionary trajectories major lineages. distribution an overall indicator diversity. diversity generally decreased. A decrease would diverse habitat structure, which typical environment, no longer existed after transition occurred deposition ULB. After hiatus 1.0 million years, UNB free forest woodland patches can be characterized open