A new vertebrate fauna from the Cretaceous Red Sandstone Group, Rukwa Rift Basin, Southwestern Tanzania

Abstract

The Rukwa Rift Basin Project was initiated to conduct exploratory field paleontology in poorly sampled terrestrial strata in southern and western Tanzania. Here we report the discovery of a series of new fossiliferous localities from Red Sandstone Group deposits in the Rukwa Rift Basin. These localities contain a diverse Cretaceous terrestrial/freshwater vertebrate fauna that consists of members of several major clades, including fishes, turtles, crocodyliforms, dinosaurs and mammals. Expeditions conducted in the austral summers of 2002–05 have identified numerous fossil-bearing localities, with specimens ranging from isolated elements to semi-articulated sauropod and theropod dinosaurs. Notable among the finds are the most complete mammal specimen recovered from the Cretaceous of continental Africa, megaloolithid dinosaur eggshell, and both theropod and sauropod dinosaurs. Given the scarcity of Cretaceous terrestrial faunas from sub-equatorial Africa, this portion of the East Africa Rift System holds great promise for providing new paleontological data that will contribute to testing and refining a number of biogeographic hypotheses that have been advanced to explain Gondwanan vertebrate distributions in the latter half of the Mesozoic.