Abstract. The well-known Late Jurassic to Early Cretaceous Tendaguru Beds of southern Tanzania have yielded fossil plant remains, invertebrates and vertebrates, notably dinosaurs, of exceptional scientific importance. Based on data of the German-Tanzanian Tendaguru Expedition 2000 and previous studies, and in accordance with the international stratigraphic guide, we raise the Tendaguru Beds to formational rank and recognise six members (from bottom to top): Lower Dinosaur Member, Nerinella Member, Middle Dinosaur Member, Indotrigonia africana Member, Upper Dinosaur Member, and Rutitrigonia bornhardti-schwarzi Member. We characterise and discuss each member in detail in terms of derivation of name, definition of a type section, distribution, thickness, lithofacies, boundaries, palaeontology, and age. The age of the whole formation apparently ranges at least from the middle Oxfordian to the Valanginian through Hauterivian or possibly Aptian. The Tendaguru Formation constitutes a cyclic sedimentary succession, consisting of three marginal marine, sandstone-dominated depositional units and three predominantly coastal to tidal plain, fine-grained depositional units with dinosaur remains. It represents four third-order sequences, which are composed of transgressive and highstand systems tracts. Sequence boundaries are represented by transgressive ravinement surfaces and maximum flooding surfaces. In a more simple way, the depositional sequences can be subdivided into transgressive and regressive sequences/systems tracts. Whereas the transgressive systems tracts are mainly represented by shallow marine shoreface, tidal channel and sand bar sandstones, the regressive systems tracts predominantly consist of shallow tidal channel, tidal flat, and marginal lagoonal to supratidal deposits.
The well-known Late Jurassic to Early Cretaceous Tendaguru Beds of southern Tanzania have yielded fossil plant remains, invertebrates and vertebrates, notably dinosaurs, of exceptional scientific importance. Based on data of the German-Tanzanian Tendaguru Expedition 2000 and previous studies, and in accordance with the international stratigraphic guide, we raise the Tendaguru Beds to formational rank and recognise six members (from bottom to top): Lower Dinosaur Member, <i>Nerinella</i> Member, Middle Dinosaur Member, <i>Indotrigonia africana</i> Member, Upper Dinosaur Member, and <i>Rutitrigonia bornhardti-schwarzi</i> Member. We characterise and discuss each member in detail in terms of derivation of name, definition of a type section, distribution, thickness, lithofacies, boundaries, palaeontology, and age. The age of the whole formation apparently ranges at least from the middle Oxfordian to the Valanginian through Hauterivian or possibly Aptian. The Tendaguru Formation constitutes a cyclic sedimentary succession, consisting of three marginal marine, sandstone-dominated depositional units and three predominantly coastal to tidal plain, fine-grained depositional units with dinosaur remains. It represents four third-order sequences, which are composed of transgressive and highstand systems tracts. Sequence boundaries are represented by transgressive ravinement surfaces and maximum flooding surfaces. In a more simple way, the depositional sequences can be subdivided into transgressive and regressive sequences/systems tracts. Whereas the transgressive systems tracts are mainly represented by shallow marine shoreface, tidal channel and sand bar sandstones, the regressive systems tracts predominantly consist of shallow tidal channel, tidal flat, and marginal lagoonal to supratidal deposits. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.200900004" target="_blank">10.1002/mmng.200900004</a>
Abstract The Miocene mica‐clay deposits of Groß Pampau (northern Germany) are well known for their diverse assemblages of marine mammals. Despite numerous systematic and biostratigraphic studies, an in‐depth palaeoecological analysis of its molluscan assemblages and a comprehensive palaeoenvironmental reconstruction are lacking. Here, we integrate new faunal, sedimentological and geochemical data to reconstruct the marine palaeoecosystem of the Upper Miocene sedimentary succession of Groß Pampau, and to identify the drivers controlling the composition, ecological structure and temporal dynamics of its macrobenthic molluscan assemblages. Fossil evidence, coupled with analyses of clay mineral composition, grain size distribution and geochemical data (total organic carbon, total nitrogen, δ 13 C, δ 18 O, δ 15 N of sediment and shells), suggests a warm–temperate, mesotrophic, low‐energy, offshore marine setting mostly below storm wave base and a pronounced surface‐to‐bottom water temperature gradient. Low variability in sedimentological and geochemical signals indicates generally stable physicochemical conditions, whereas the occurrence of the opportunistic species Varicorbula gibba suggests occasionally unfavourable bottom conditions, possibly related to transient hypoxia. Canonical correspondence analysis indicates that the distribution of molluscan assemblages correlates with total organic carbon and nitrogen content, suggesting organic matter availability at the sea floor as a controlling factor. A pattern of repetitive punctuated stasis of molluscan assemblages is defined by the temporal persistence in taxonomic and ecological composition, occasionally interrupted by shifts to a different faunal configuration. We suggest that both stable environmental conditions and biotic interactions (i.e. the top‐down control exerted by carnivorous gastropods and environmental modification by ubiquitous burrowing deposit feeders) probably contributed to the observed temporal stability.
Here we report on a new dyrosaurid from the latest Cretaceous Kababish Formation, Sudan, which was previously unknown to yield fossil macrovertebrates and had remained largely unstudied. The almost complete, partially articulated skeleton was recovered in situ near Jebel Abyad. The skeleton is almost 7 m in length and preserves an almost complete skull and partly articulated postcranium with several disarticulated osteoderms. The material is assigned to Dyrosauridae based on the presence of elongate supratemporal fenestrae, occipital tuberosities, and a reduced seventh alveolus on the mandible. Morphological features of the skull and mandible differ from other members of this family suggesting that this taxon represents a new genus and species of dyrosaurid. A unique feature of the new taxon is that the humerus is wedge-shaped and longer than femur. Phylogenetic analyses using parsimony and Bayesian inference posit that the new taxon is deeply nested in Dyrosauridae as a sister taxon to a clade including Arambourgisuchus, Dyrosaurus, Acherontisuchus, Hyposaurus, Congosaurus, Rhabdognathus, Atlantosuchus, and Guarinisuchus. The occurrence of the new dyrosaurid within the Kababish Formation potentially extends the temporal range of the Dyrosauridae to the Campanian and supports previous hypotheses of an African origin for this family.
