The majority of dinosaur fossils found in Thailand are large, long-necked sauropods. Yet, in the Khok Kruat Formation, the youngest dinosaur-charged Mesozoic rock layer in Thailand, fossil remains are few and usually incomplete.
Paleontologists in northeastern Thailand have announced the identification of a giant new species of long-necked sauropod dinosaur, now the largest dinosaur found to date in Southeast Asia. The fossils, which were discovered near a pond more than a decade ago, have been painstakingly studied by a team of researchers from the University College London (UCL), Mahasarakham University, Suranaree University of Technology, and Thailand’s Sirindhorn Museum.
The fossils, first uncovered near a pond about ten years ago, have been carefully studied by a team from University College London (UCL), Mahasarakham University, Suranaree University of Technology, and Thailand’s Sirindhorn Museum.
Their findings, published in Scientific Reports, detail a specimen of extraordinary size and importance that will enhance the fossil record of this region back through deep time.
Scientists estimated the length and weight of this dinosaur from its vertebrae, ribs, pelvis, and leg bones to be about 27 meters (89 feet) long and 27 tonnes, equivalent to about nine adult Asian elephants. The sheer size of this animal is underscored by a single front leg bone measuring 1.78 m, the height of an upright human being!
The newly found species is called Nagatitan chaiyaphumensis. It takes its name from Naga, a mythical serpent in Thai and Southeast Asian folklore, and from the Titans, the giants of Greek mythology. The species name is in honor of Chaiyaphum province, the locality of the fossils. With that, Thailand now has the 14th of its officially named dinosaurs.
Nagatitan chaiyaphumensis was a sauropod, a type of dinosaur usually recognized by popular genera like Diplodocus and Brontosaurus: large-bodied herbivores with long necks and tails. This number dates back an estimated 100 to 120 million years ago to Early Cretaceous times.
Lead researcher Thitiwoot (Perth) Sethapanichsakul, a Thai PhD student at UCL Earth Sciences, explained:
“Our dinosaur is big by most people’s standards, at least 10 tonnes heavier than Dippy the Diplodocus. But it’s still smaller than giants like Patagotitan (60 tonnes) or Ruyangosaurus (50 tonnes).”
The team calls Nagatitan “the last titan” of Thailand because it was found in the country’s youngest dinosaur‑bearing rocks. Later layers turned into shallow seas, meaning this may be the final large sauropod ever discovered in Southeast Asia.
This mosaic of the environment in that region was dry to semi-dry, a habitat where sauropods seem to have thrived. The long necks and tails of some species were thought to function as heat-sink structures, suggesting they helped dissipate excessive heat. This fossil site also suggests an ancient river ecosystem teeming with fish, freshwater sharks, and crocodiles, the beloved habitat of Nagatitan, which once called this place home.
The giant sauropod didn’t live alone. Its habitat was shared with a lively mix of prehistoric creatures:
Smaller plant‑eaters like iguanodontians and early ceratopsians (relatives of Triceratops), Huge predators such as carcharodontosaurians and spinosaurids, Pterosaurs, flying reptiles that hunted fish along the river system.
Researchers classified Nagatitan as a somphospondylan sauropod, a group that spread widely about 120 million years ago. More specifically, it belonged to the Euhelopodidae, a subgroup found only in Asia.
What makes Nagatitan stand out are its distinctive features in the spine, pelvis, and leg bones. To help the public imagine its scale, a life‑size reconstruction is now on display at the Thainosaur Museum at Asiatique in Bangkok, where visitors can walk beneath the shadow of Southeast Asia’s largest known dinosaur.
Co-author Professor Paul Upchurch of UCL Earth Sciences said: “This discovery comes out of a new collaboration between UCL and colleagues in Thailand. The material was studied both in Thailand and at UCL. 3D scanning and printing have meant that we can study the specimen and collect data without having to travel (good for reducing carbon footprint).”
Journal Reference:
- Thitiwoot Sethapanichsakul, Sasa-On Khansubha, Sita Manitkoon, Rattanaphorn Hanta, Philip D. Mannion, Paul Upchurch. The first sauropod dinosaur from the Lower Cretaceous Khok Kruat Formation of Thailand enriches the diversity of somphospondylan titanosauriforms in Southeast Asia. Scientific Reports, 2026; 16 (1) DOI: 10.1038/s41598-026-47482-x