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(1-3), most titanosaurs are known only from fragmentary postcranial skeletons and rare, isolated skull elements(4-9). 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(10-13)). The inclusion of cranial data from Rapetosaurus also lays to rest questions concerning the phylogeny of the enigmatic Mongolian genera Nemegtosaurus and Quaesitosaurus(14,15). In spite of their elongated, diplodocoid-like skulls, all three taxa are now firmly nested within Titanosauria.