The last of the dinosaur titans: a new sauropod from Madagascar

The Titanosauria, the last surviving group of the giant sauropod dinosaurs, attained a near-global distribution by the close of the Cretaceous period (65 Myr ago). With the exception of a few new discoveries in Argentina, most titanosaurs are known only from fragmentary postcranial skeletons and rare, isolated skull elements. Here we describe the most complete titanosaur yet discovered. Rapetosaurus krausei gen. et sp. nov., from the Maevarano Formation of Madagascar, provides a view of titanosaur anatomy from head to tail. A total-evidence phylogenetic analysis supports a close relationship between brachiosaurids and titanosaurs (Titanosauriformes). The inclusion of cranial data from Rapetosaurus also lays to rest questions concerning the phylogeny of the enigmatic Mongolian genera Nemegtosaurus and Quaesitosaurus. In spite of their elongated, diplodocoid-like skulls, all three taxa are now firmly nested within Titanosauria.