Uragasaurus kalasinensis: A new mamenchisaurid from Thailand reshapes Southeast Asian sauropod history
A new mamenchisaurid sauropod, Uragasaurus kalasinensis, is described from Thailand’s Phu Kradung Formation based on a well-preserved anterior dorsal vertebra (PRC 460). Phylogenetic analyses place it as an early-branching member of Mamenchisauridae, extending the clade’s Southeast Asian distribution. Notable features include a unique Y-shaped intraprezygapophyseal lamina and camellate internal pneumaticity revealed by CT, with implications for Late Jurassic age of the formation and sauropod diversity in Southeast Asia during the Jurassic–Cretaceous transition.