A massive new dinosaur discovered in Thailand may have been one of the last giant sauropods to roam Southeast Asia. The towering “last titan” stretched nearly 90 feet long and weighed as much as nine elephants.
Southeast Asia’s Largest Dinosaur Discovered in Thailand
Scientists have identified a massive new dinosaur species in Thailand, now considered the largest ever discovered in Southeast Asia. The giant plant-eater, named Nagatitan chaiyaphumensis, was described in a study led by researchers from University College London (UCL), Mahasarakham University, Suranaree University of Technology, and the Sirindhorn Museum in Thailand.
The fossils were first uncovered about 10 years ago near a pond in northeastern Thailand. Researchers later analyzed bones from the dinosaur’s spine, ribs, pelvis, and legs to determine the size and identity of the enormous animal.
One front leg bone measured 1.78 meters long (as long as a human). Based on the fossil evidence, scientists estimate the dinosaur reached about 27 meters in length and weighed roughly 27 tonnes – about the same as nine adult Asian elephants.
The Meaning Behind Nagatitan
The newly named species combines references from both Southeast Asian and Greek mythology. “Naga” refers to a legendary serpent from Thai and Southeast Asian folklore, while “Titan” refers to the giants of Greek mythology. The species name chaiyaphumensis recognizes Chaiyaphum province, where the fossils were discovered.
Nagatitan chaiyaphumensis is the 14th dinosaur species officially named in Thailand.
The dinosaur belonged to the sauropods, the famous group of long-necked and long-tailed plant eaters that included animals such as Diplodocus and Brontosaurus. It lived during the Early Cretaceous period between 100 and 120 million years ago.
Lead author Thitiwoot (Perth) Sethapanichsakul, a Thai PhD student at UCL Earth Sciences, said: “Our dinosaur is big by most people’s standards – it likely weighed at least 10 tonnes more than Dippy the Diplodocus (Diplodocus carnegii). However, it is still dwarfed by sauropods like Patagotitan (60 tonnes) or Ruyangosaurus (50 tonnes).
“We refer to Nagatitan as ‘the last titan’ of Thailand. That is because it was discovered in Thailand’s youngest dinosaur-bearing rock formation. Younger rocks laid down towards the end of the time of the dinosaurs are unlikely to contain dinosaur remains because the region by then had become a shallow sea. So this may be the last or most recent large sauropod we will find in Southeast Asia.”
Ancient Thailand’s Dinosaur Ecosystem
Researchers believe the environment where Nagatitan lived was arid to semi-arid during the Early Cretaceous period. Sauropods appear to have thrived in these conditions, possibly using their long necks and tails to help regulate body heat.
The fossil site also suggests the region once contained winding river systems populated by fish, freshwater sharks, and crocodiles.
The giant dinosaur likely shared its habitat with smaller plant-eating dinosaurs, including iguanodontians and early ceratopsians (cousins of the Triceratops). Large predators such as carcharodontosaurians and spinosaurids also lived in the area, along with flying reptiles known as pterosaurs that hunted fish from the rivers.
Unique Features of the Giant Sauropod
Scientists classified Nagatitan as a somphospondylan sauropod – a subgroup that became widespread around 120 million years ago. More specifically, the dinosaur belonged to Euhelopodidae, a branch of somphospondylan sauropods known only from Asia.
Researchers identified the species by a unique combination of features in its spine, pelvis, and leg bones. A full size reconstruction of the dinosaur is now displayed at the Thainosaur Museum at Asiatique in Bangkok.
Sethapanichsakul said, “My dream is to continue pushing to get Southeast Asian dinosaurs recognized internationally. More international collaborations between Thailand and other institutions like UCL can further our understanding of the region’s paleobiology and apply it to a global context. This all starts with identifying and describing the specimens we have found first. We have a large collection of sauropod fossils that have not yet been formally described – these may include a number of new species.
“I’ve always been a dinosaur kid. This study doesn’t just establish a new species but also fulfills a childhood promise of naming a dinosaur.”
International Dinosaur Research Collaboration
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 has meant that we can study the specimen and collect data without having to travel (good for reducing carbon footprint).
“We have had a long-standing interest in the evolution of these gigantic plant eaters and have good collaborative links with researchers around the world. It is great to work with Thai colleagues and start to get insights into what was happening in Southeast Asia during the Jurassic and Cretaceous.”
UCL’s dinosaur evolution group includes five academics working closely with the Natural History Museum. The broader team also includes four research fellows and postdoctoral researchers, along with more than 10 PhD students. Several of the students focus on dinosaur evolution, while others study vertebrates such as crocodiles and birds.
Project leader and National Geographic Explorer Dr. Sita Manitkoon, a researcher at the Palaeontological Research and Education Centre at Mahasarakham University, said: “Although Thailand is a small country within Asia, we have a very high diversity in dinosaur fossils, possibly the third most abundant in Asia in terms of dinosaur remains. We’ve only really been studying dinosaurs in Thailand about 40 years (since the first dinosaur was named in 1986), and already we have a surge of younger generation paleontologists, who are actively undertaking research and promoting paleontology and its importance within the country.”
Reference: “The first sauropod dinosaur from the Lower Cretaceous Khok Kruat Formation of Thailand enriches the diversity of somphospondylan titanosauriforms in southeast Asia” by Thitiwoot Sethapanichsakul, Sasa-On Khansubha, Sita Manitkoon, Rattanaphorn Hanta, Philip D. Mannion and Paul Upchurch, 14 May 2026, Scientific Reports.
DOI: 10.1038/s41598-026-47482-x
The study was funded by the National Geographic Society.
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