Overview
- A team led by Apirut Nilpanapan published a paper on Wednesday, July 8, 2026, formally naming Uragasaurus kalasinensis from an isolated anterior dorsal vertebra catalogued as holotype PRC 460 and housed at Mahasarakham University’s Palaeontological Research and Education Centre.
- The species diagnosis rests on distinct external features and CT data that show elongated teardrop pneumatic fossae on the transverse processes, a Y‑shaped arrangement of intraprezygapophyseal laminae, a shallow subtriangular pleurocoel, and a camellate internal pneumatic structure inside the centrum.
- Phylogenetic analyses in the paper recover Uragasaurus as a near‑basal, early‑diverging member of Mamenchisauridae, making it the first formally named mamenchisaurid from Thailand and extending confirmed records of the family into mainland Southeast Asia.
- The fossil was found at the Phu Noi locality in Kalasin Province within the lower part of the Phu Kradung Formation, and the authors use the occurrence to support an Upper Jurassic age for that interval while noting that precise radiometric dating remains unresolved and nearby sauropod bones were not confidently assigned to the new taxon.
- Researchers say the find strengthens links between Thai and contemporaneous Chinese Jurassic faunas and underlines the need for further fieldwork, CT imaging, and improved dating to test whether the associated fragments belong to Uragasaurus and to refine its age and ecology.