‘Last titan’ of Thailand discovered, and it’s the longest-necked dinosaur on record from Southeast Asia
Gigantic fossils discovered in Thailand reveal the “last titan”, a long-necked dinosaur that lived 120 million years ago when the region was semi-arid, a new study suggests.
Double Nagatitan chaiyaphumensisThe new species is the largest sauropod, or long-necked dinosaur, found to date in Southeast Asia. It probably measured about 90 feet (27 meters) in length and weighed about 30 tons (27 metric tons), according to a study published Thursday (May 14) in the journal Scientific reports.
“Our dinosaur is big by most people’s standards – it probably weighed at least 10 tonnes [11 tons] more than Dippy the Diplodocus (Diplodocus carnegii),” studies the first author Thitiwoot Sethapanichsakulpaleontologist at University College London, said in a statement. However, it is not the largest known sauropod, weighing less than half that of its South American relatives. Patagotitan And Argentinosaurus.
The research team discovered the fossils from the Khok Kruat Formation in Chaiyaphum Province, northeastern Thailand. A local resident first spotted the fossils in 2016 in a bed of bones at the edge of a drying pond.
Among the fossils recovered are several vertebrae, pelvic bones and leg bones, including the dinosaur’s right femur, or thigh bone. Although the femur broke into several pieces, scientists estimated that it measured about 2 meters in length, about the height of a tall human.
Paleontologist Thitiwoot Sethapanichsakul stands next to the humerus, or front leg bone, of Nagatitan chaiyaphumensis.
(Image credit: Thitiwoot Sethapanichsakul)
N. chaiyaphumensis was a type of dinosaur known as the somphospondylan sauropod, a subgroup of large, long-necked dinosaurs that lived from the late Jurassic to the Cretaceous. Fossils of this group have been discovered on every continent. The forms of N. chaiyaphumensisThe vertebrae and leg bones distinguish it from other previously known sauropods.
The team named the sauropod genus Nagatitan after Naga, “the mythological snake-like creature found in various Asian cultures, particularly in northeastern Thailand, often associated with water and Buddhism,” they wrote in the study. “Titan”, meanwhile, comes from the giants of Greek mythology. The name of the species chaiyaphumensis owes its name to the province of Chaiyaphum.
During the Cretaceous (145 to 66 million years ago), northeastern Thailand would have been a semi-arid environment, and N. chaiyaphumensis would have used its long body and large surface area to release heat and keep cool. The fossil site was probably part of a river system at that time, so N. chaiyaphumensis would have lived alongside crocodiles, fish and piscivores pterosaurs.
A skeletal reconstruction of Nagatitan chaiyaphumensiswith the discovered bones highlighted in yellow.
(Image credit: Thitiwoot Sethapanichsakul et al)
The fossils were embedded in Thailand’s youngest rocks that still contain dinosaur fossils. Although additional rock layers have accumulated at the top of the N. chaiyaphumensis fossils, specific conditions later in the Cretaceous period likely prevented the formation of later dinosaur fossils, the researchers said.
“Younger rocks deposited near the end of the dinosaur age are unlikely to contain dinosaur remains, because the area had become a shallow sea by then,” Sethapanichsakul said. “This may be the last or newest large sauropod we will find in Southeast Asia.”
Sethapanichsakul, T. et al. 2026 The first sauropod dinosaur from the Lower Cretaceous Khok Kruat Formation in Thailand enriches the diversity of somphospondylian titanosauriforms in Southeast Asia. Sci. 16:12467. https://doi.org/10.1038/s41598-026-47482-x
What do you know about the king of the dinosaurs? Test your knowledge with our T. rex quiz!
