Article: New material of an Early Cretaceous titanosaurid sauropod dinosaur from Malawi
Louis L. Jacobs, Dale A. Winkler, William R. Downs and Elizabeth M. Gomani
Compared to their Late Jurassic record, sauropod dinosaurs are poorly known in the Cretaceous Period between 144 Ma and the terminal Cretaceous extinction event at 66 Ma. The Titanosauridae are the most widespread and common of Cretaceous sauropods. The titanosaurid species from the Dinosaur Beds of Malawi, Africa, here referred to Malawisaunis dixeyi comb, nov., has precoelous anterior caudal vertebrae, a characteristic of the family, but middle and distal caudals with gently biconcave ends. Caudal neural spines are low, a feature that is shared with South American Saltasaurus and North American Alamosaurus. A premaxilla of Malawisaurus, the first known for the family, is primitive in having the external nares placed far anterior, demonstrating that this titanosaurid has a blunter snout than other sauropods. Flattened teeth in Malawisaurus suggest that pencil-shaped teeth may have evolved more than once within the Sauropoda. Titanosaurids probably originated at a time when other sauropod families were differentiating in the Late Jurassic. The Titanosauridae is the longest lived group of sauropods.