and frequent reworking. This basal succession passes upward in cross-bedded sandstone and minor siltstone and claystone with flaser or lenticular bedding that are interpreted as tidal flat and tidal channel deposits. Horizontal to low-angle cross-bedded, fine-grained sandstone with intercalated bivalve pavements indicates tidal currents that operated in small flood and ebb tidal deltas and along the coast. Stacked successions of trough cross-bedded, medium- to coarse-grained sandstone of the upper part of the Indotrigonia africana Member are interpreted as tidal channel and sand bar deposits. At some places in the surroundings of Tendaguru Hill, these sediments interfinger with oolitic limestone layers that represent high-energy ooid shoals. In the Tingutinguti stream section, the Indotrigonia africana Member exhibits several up to thick, poorly sorted, conglomeratic sandstone beds. They contain mud clasts, reworked concretions and/or accumulations of thick-shelled bivalves (mainly Indotrigonia africana and Seebachia janenschi), and exhibit megaripple surfaces. These conglomeratic sandstone layers are interpreted as storm deposits. In the Dwanika and Bolachikombe stream sections, and in a small tributary of the Bolachikombe creek, a discrete, up to thick conglomerate in the lower portion of the Indotrigonia africana Member displays evidence of a tsunami deposit. Overall, lithofacies and the diverse macroinvertebrate and microfossil assemblages of the Indotrigonia africana Member suggest a shallow marine environment. Based on the diverse mesoflora and the abundance of Classopollis, a nearby vegetated hinterland is postulated that was dominated by xerophytic conifers. Upper Dinosaur Member The small-scale trough and ripple cross-bedded fine-grained sandstone at the base of the Upper Dinosaur Member is interpreted as tidal flat deposits. Unfossiliferous sandstone in the upper part was most likely deposited in small fluvial channels in a coastal plain environment, whereas argillaceous deposits were laid down in still water bodies such as small lakes and ponds. Rare occurrences of the ostracod Cypridea and charophytes signal the influence of freshwater, whereas the sporadic occurrence of marine invertebrates suggests a depositional environment close to the sea. Rutitrigonia bornhardti-schwarzi Member Fining upward sequences of the basal part of the Rutitrigonia bornhardti-schwarzi Member are interpreted as tidal channel fills, the overlying fine-grained sandstone, silt- and claystone as tidal flat deposits. From the immediate surroundings of Tendaguru Hill, invertebrates and vertebrates are poorly known and limit the palaeoenvironmental interpretation of this member. The composition of the land-derived sporomorph assemblage suggests a terrestrial vegetation which was dominated by cheirolepidiacean conifers in association with ferns. Excavation history The Tendaguru Beds as