Data from: A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs

Titanosauria was the most diverse and successful lineage of sauropod dinosaurs. This clade had its major radiation during the middle Early Cretaceous and survived up to the end of that period. Among sauropods, this lineage has the most disparate values of body mass, including the smallest and largest sauropods known. Although recent findings have improved our knowledge on giant titanosaur anatomy, there are still many unknown aspects about their evolution, especially for the most gigantic forms and the evolution of body mass in this clade. Here we describe a new giant titanosaur, which represents the largest species described so far and one of the most complete titanosaurs. Its inclusion in an extended phylogenetic analysis and the optimization of body mass reveals the presence of an endemic clade of giant titanosaurs inhabited Patagonia between the Albian and the Santonian. This clade includes most of the giant species of titanosaurs and represents the major increase in body mass in the history of Titanosauria.

泰坦龙类（Titanosauria）是蜥脚类恐龙（sauropod dinosaurs）中多样性最高且演化最为成功的支系。该演化支（clade）于早白垩世中期发生了主要辐射演化，并存续至该地质时期结束。在蜥脚类恐龙中，该支系的体重范围差异极大，涵盖了目前已知体型最小和最大的蜥脚类恐龙。尽管近期的研究进展提升了我们对巨型泰坦龙类解剖结构的认知，但关于其演化的诸多方面仍有待阐明，尤其是体型最为庞大的类群以及该演化支的体重演化机制。本文描述了一种全新的巨型泰坦龙类，它是目前已命名的体型最大的泰坦龙类物种，同时也是保存最为完整的泰坦龙类类群之一。将其纳入扩展后的系统发育分析（phylogenetic analysis）并开展体重演化优化分析后，研究团队发现了一个栖息于巴塔哥尼亚（Patagonia）、繁盛于阿尔必阶（Albian）至桑托阶（Santonian）的巨型泰坦龙类特有演化支。该演化支涵盖了绝大多数巨型泰坦龙类物种，代表了泰坦龙类演化历史中最为显著的体重增长事件。