basement consisting of gneiss. The contact contains a large hiatus, a missing sequence of stratigraphy, spanning the Paleozoic, Triassic and Early Jurassic. The formation is unconformably overlain by late Early Cretaceous sediments of the Makonde Formation, that forms the top of several plateaus; Namunda, Rondo, Noto, and Likonde-Kitale. Based on extended geological and paleontological observations the "Tendaguruschichten" (Tendaguru Beds) were defined by Werner Janensch as expedition leader and Edwin Hennig in 1914 to define a sequence of Late Jurassic to Early Cretaceous strata, exposed in the Tendaguru area, which is named after Tendaguru Hill. Stratigraphy The Tendaguru is divided into 6 members, which represent different depositional environments, with the 'Dinosaur Beds' representing terrestrial facies while the beds with genus/species names represent marine interbeds with shallow marine to lagoonal facies. In ascending order these are: the Lower Dinosaur Member, the Nerinella Member, the Middle Dinosaur Member, Indotrigonia africana Member, the Upper Dinosaur Member, and the Rutitrigonia bornhardti-schwarzi Member. Paleogeography and depositional environment Paleogeography The Tendaguru Formation was deposited in the Mandawa Basin, a post-Karoo, Mesozoic rift basin located between the Ruvu Basin and Rufiji Trough to the north and the Ruvuma Basin to the south. To the west of the basin, Archean and Early Proterozoic basement rocks crop out. The main rift phase in present-day southeastern Africa led to the separation of Madagascar and the then-connected Indian subcontinent happened during the Early Cretaceous. The Songo Songo and Kiliwani gas fields are located just offshore the basin. At time of deposition was undergoing a semi-arid climate with coastal influences that maintained somewhat higher moisture levels than seen inland. The upper parts of the formation, the Middle Dinosaur and Rutitrigonia bornhardti-schwarzi Members in particular, showed prevailing semiarid conditions with pronounced dry seasons, based on palynologic analysis. The Tendaguru fauna was stable through the Late Jurassic. During the Late Jurassic and Early Cretaceous, the Gondwana paleocontinent was breaking up and the separation of the Laurasian and Gondwana supercontinents resulted from the connection of the Tethys Ocean with the proto-Atlantic and the Pacific Ocean. In addition, the South Atlantic developed towards the end of the Late Jurassic with the separation of South America and Africa. Africa became increasingly isolated from most other continents by marine barriers from the Kimmeridgian into the Early Cretaceous, but retained a continental connection with South America. Global sea levels dropped significantly in the Early Jurassic and remained low through the