Palaeontologists describe Uragasaurus kalasinensis, a new genus and species from the lower Phu Kradung Formation of northeastern Thailand. A well-preserved anterior dorsal vertebra, including CT-visible internal pneumatic structure, supports an early-diverging mamenchisaurid placement. It is the first formally named mamenchisaurid from Thailand, although the holotype evidence is centred on a single vertebra.
Key findings
- The vertebra shows a distinctive character combination, including a Y-shaped laminar configuration and camellate pneumatic structure in the centrum. Phylogenetic analyses placed it as an early-diverging mamenchisaurid. Its lower Phu Kradung occurrence supports a Late Jurassic age and expands knowledge of Southeast Asian sauropod diversity near the Jurassic-Cretaceous transition.
Why this matters globally
Mamenchisaurids are best documented in China. A formally named Thai taxon tests hypotheses about East Asian terrestrial dispersal and supplies a regional reference for faunal and stratigraphic correlation.
Thai researcher contribution
Mahasarakham University and the Khon Kaen Geopark Association turned northeastern Thai fossil heritage into international evidence spanning preservation, CT anatomy, taxonomy, evolution and geologic time.
Limitations to consider
The taxon is based on one anterior dorsal vertebra. Features may vary by serial position, ontogeny or taphonomic distortion. Phylogenetic placement depends on matrices with substantial missing data, and biostratigraphic age support is not equivalent to absolute dating.