Massive 120-Million-Year-Old Long-Necked Dinosaur Discovered in Thailand

Paleontologists have identified a new species of long-necked sauropod dinosaur from Thailand, now recognized as the largest known dinosaur of its kind from Southeast Asia. The discovery, announced on May 17, 2026, sheds light on the region’s prehistoric biodiversity and challenges previous assumptions about the size and diversity of dinosaurs in this part of the world.

The newly named species, Nagatitan chaiyaphumensis, was unearthed in Chaiyaphum Province, northeastern Thailand, where researchers from University College London (UCL), Mahasarakham University, Suranaree University of Technology, and Sirindhorn Museum have been studying fossil remains since 2016. The name reflects its origin, with “Naga” referencing the mythical serpent-like creatures of Thai culture and “titan” acknowledging its massive size. The species designation, chaiyaphumensis, honors the province where the fossils were discovered.

Estimates based on the fossilized bones—including vertebrae, ribs, pelvic fragments, and a leg bone measuring 1.78 meters—suggest the dinosaur weighed approximately 27 tonnes and stretched up to 27 meters in length, comparable to the size of a blue whale. This makes it significantly larger than previously known Southeast Asian dinosaurs, such as Siamosaurus suteethorni, discovered in the same region in 1986. The discovery also underscores the region’s status as a hotspot for dinosaur fossils, with Nagatitan marking Thailand’s 14th unique dinosaur species.

While Nagatitan is not the largest dinosaur ever discovered—titans like Patagotitan (60 tonnes) and Ruyangosaurus (50 tonnes) dwarf it—the species represents a significant milestone for Southeast Asian paleontology. Its size and anatomical features provide new insights into the evolution of sauropods, a group known for their long necks and massive bodies, which dominated Earth’s ecosystems during the Late Jurassic and Early Cretaceous periods.

Lead researcher Thitiwoot Sethapanichsakul, a Thai PhD student at UCL’s Earth Sciences department, emphasized the uniqueness of the find in a statement attributed to verified reporting. “Our dinosaur is big by most people’s standards—it likely weighed at least 10 tonnes more than ‘Dippy the Diplodocus’ (Diplodocus carnegii),” Sethapanichsakul said. “However, This proves still dwarfed by sauropods like Patagotitan or Ruyangosaurus.” The comparison to Diplodocus, a well-known North American sauropod, highlights how Nagatitan pushes the boundaries of known dinosaur sizes in its region.

### A Window into the Cretaceous Ecosystem

The discovery of Nagatitan also offers clues about the ecological conditions of the region approximately 120 million years ago, during the Early Cretaceous period. The presence of such a massive herbivore suggests thriving flora capable of supporting giant creatures, likely including ferns, conifers, and early flowering plants. Researchers speculate that the dinosaur’s long neck would have allowed it to browse the treetops, giving it a competitive advantage in dense forests.

While the fossil record in Southeast Asia remains incomplete, the find aligns with broader trends in global paleontology, where new species continue to be identified in regions once thought to have limited dinosaur activity. The Thai fossil site, in particular, has yielded a diverse array of species, including theropods, ornithopods, and other sauropods, painting a picture of a dynamic prehistoric landscape.

### What Comes Next for the Research?

Further analysis of the Nagatitan fossils will focus on refining size estimates, reconstructing its skeletal structure, and comparing it to other sauropods. Scientists also hope to uncover more fossils from the same site, which could reveal additional species or provide a clearer picture of how these dinosaurs interacted with their environment. The research team plans to publish detailed findings in a peer-reviewed journal, though no specific timeline has been confirmed.

For now, the discovery serves as a reminder of how much remains unknown about Earth’s prehistoric past. While Nagatitan may not hold the title of the largest dinosaur ever found, its sheer size and the circumstances of its discovery make it a landmark in Southeast Asian paleontology—a testament to the region’s rich fossil heritage and the ongoing quest to uncover the stories buried beneath its soil.