Discovery of a new dinosaur genus
A new study led by Philip Mannion, former Humboldt-Fellow at the Museum fuer Naturkunde Berlin (MfN) and with contribution from Daniela Schwarz, curator for the dinosaur fossils at the MfN, deals with the fossil fragments of dinosaurs from Tanzania. A new sauropod genus and species was found and described under the scientific name of Wamweracaudia kerajei. This name was chosen to honor the Wamwera, the most populous tribe in the Lindi-region of Tanzania. The results of the study demonstrate that the rich Jurassic sauropod fauna from the Tendaguru region was even more diverse than previously thought.
The Late Jurassic Tendaguru Formation of Tanzania, southeastern Africa, records a rich sauropod fauna with at least 7 valid sauropod species described so far. Whereas some of these sauropods, such as the famous Giraffatitan and the relatively small Dicraeosaurus, are represented by rather complete skeletal material, some of the other sauropods were described on the basis of incomplete remains, which makes it difficult to assess their taxonomic affinities. This refers in particular to the genera Janenschia, Tendaguria and Australodocus, which have played a prominent role in the discussion of the origin of titanosaurs, a predominantly Cretaceous sauropod group. These sauropods are therefore important sources for reconstructing the evolution of sauropods.
A new study under the lead author Philip Mannion, former Humboldt Fellow at the Museum für NAturkunde Berlin (MfN), and with contribution of Daniela Schwarz, curator for the dinosaur fossils at the MfN, redescribes these taxa Janenschia, Tendaguria and Australodocus and presents the hitherto largest phylogenetic analysis for sauropods to explore their placement within more derived sauropods. The work was supported by information gained from computed tomographic images of the internal of the vertebral bones. As a result from this study, the sauropod genus Janenschia can be confirmed to be valid, but represents a much more basal sauropod than previously assumed. Only Australodocus bohetii can be confirmed to be a non-titanosaurian somphospondylan sauropods, and therebey represent the only known pre-Cretaceous representative of that group. With the help of the computed tomographic images, the internal hollows of the 1 m wide dorsal vertebrae of the enigmatic Tendaguria tanzaniensis were displayed, a taxon that is hereby recognized as the first turiasaur from Gondwana.
The authors were even able to find a new sauropod genus within the material from Tendaguru. The term “genus” refers to a unit in the biological systematics in which one or several species are incorporated. A sequence of tail vertebrae previously assigned to Janenschia displays a number of unique features that makes it necessary to place it in a separate and new taxon Wamweracaudia keranjei, instead. This name was chosen to honor the Wamwera, the most populous tribe in the Lindi district of Tanzania, and the chief excavator of this specimen, Mohammadi Keranje. “With this designation, we demonstrate respect for the main players of the Tendaguru expedition 1909 and 1913, and we want to appreciate effectively their excellent work during the recovery of the fossil material” says Johannes Vogel, director general of the MfN. Wamweracaudia is closely related with the East Asian Jurassic sauropod group of mamenchisaurs.
“These results demonstrate that the rich Jurassic sauropod fauna from Tendaguru was even more diverse, both in species and in its unique composition of modern and rather basal sauropod taxa, than previously thought, which underlines the exceptional importance of this locality. “ says Co-Author Daniela Schwarz. The results shed also new light of the evolutionary history of sauropods, as the Tendaguru Formation apparently contains representatives of nearly all sauropod lineages known from the Middle Jurassic to the Early Cretaceous. The unmatched diversity of sauropods in the Tendaguru area is evidence of active migration of sauropods through the Central Gondwana Desert with invasions of sauropods from Euamerica, which were mixed with endemic taxa in western Gondwana. Presence of taxa like Janenschia and Wamweracaudia additionally are evidence for regional extinctions and segregation of basal sauropod groups in these parts of the world. Research around the dinosaurs from Tendaruru remains fascinating and the scientists of the MfN look forward to future collaborative research with their Tanzanian colleagues on this world heritage.
Published in: Mannion, Philip D., Schwarz, Daniela, Upchurch, Paul, and Wings, Oliver. 20xx. Taxonomic affinities of the putative titanosaurs from the Late Jurassic Tendaguru Formation of Tanzania: phylogenetic and biogeographic implications for eusauropod dinosaur evolution. Zoological Journal of the Linnean Society