ブラジルから、白亜紀初期のティタノサウルス類が発見されました。

A Complete Skull of an Early Cretaceous Sauropod and the Evolution of Advanced Titanosaurians Advanced titanosaurian sauropods, such as nemegtosaurids and saltasaurids, were diverse and one of the most important groups of herbivores in the terrestrial biotas of the Late Cretaceous. However, little is known about their rise and diversification prior to the Late Cretaceous. Furthermore, the evolution of their highly-modified skull anatomy has been largely hindered by the scarcity of well-preserved cranial remains. A new sauropod dinosaur from the Early Cretaceous of Brazil represents the earliest advanced titanosaurian known to date, demonstrating that the initial diversification of advanced titanosaurians was well under way at least 30 million years before their known radiation in the latest Cretaceous. The new taxon also preserves the most complete skull among titanosaurians, further revealing that their low and elongated diplodocid-like skull morphology appeared much earlier than previously thought.

頭骨が見つかることはまれなのですが、今回、頭骨も発見されており、ティタノサウルス類が、その初期段階から多様化を見せ始めていたことを示しているといいます。