Meet Nagatitan: Southeast Asia's largest dinosaur who weighed as much as nine Asian elephants and was 27m in length

In a discovery that has left the world shocked, a small Thai village has simply changed the world of palaeontology forever. Thousands of years later, humans still continue their research on an extinct animal species whose existence is as much of an enigma as their disappearance.

To date, every day, a discovery reveals something new and unexpected about dinosaurs. But a morning walk in a village has unearthed the deep secrets of Southeast Asia's history in the dinosaur world and family.

Meet the Nagatitan

It was a normal morning in the country's Chaiyaphum province, when a villager was walking around the countryside. They saw huge bones sticking out of the ground near a pond and notified the authorities, which led to the digging up of a new type of giant long-necked dinosaur

The Nagatitan, the largest-ever dinosaur found in South-East Asia weighted 27 tonnes, as much as nine adult Asian elephants and measured 27m in length, longer than a diplodocus. It belonged to the sauropod family of long-necked herbivores, which are believed to be the largest land animals to ever live.

The dinosaur's full name is Nagatitan chaiyaphumensis, with the "naga" referring to a serpent in South-East Asian folklore, "titan" referring to the gods in Greek mythology and chaiyaphumensis meaning "from Chaiyaphum", the province where the fossils were discovered.

It lived between 100 and 120 million years ago, around 40 million years before the Tyrannosaurus rex and is about twice the size of the creature. Scientists explain that this dinosaur developed singular anatomical characteristics such as specific bony wedges in its vertebrae differentiating it from South American relatives like Patagotitan and Argentinosaurus.

A team of researchers from the UK and Thailand identified the species from fossils found beside a pond in north-eastern Thailand a decade ago. They say the discovery sheds light on how changes in ancient climatic conditions allowed gigantic dinosaurs to develop.

Thitiwoot Sethapanichsakul, a Thai doctoral student at University College London (UCL), was the lead author of the study which was published in the Scientific Reports journal. According to the expert, the researchers referred to the nagatitan as "the last titan" of Thailand, because the fossils were found in the country'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 South-East Asia," he said.

Previously, excavation conducted between 2016 and 2024 in the province of Chaiyaphum allowed for the rescue of key skeletal pieces of this specimen, including a nearly complete femur and a humerus almost two meters long, confirming their massive scale. They belonged to a subgroup of sauropods that possessed bones with lots of internal air sacs and thin walls, traits that lightened their skeletons.

What does discovery of Nagatitan mean for the dinosaur world?

Though Thailand has conducted systematic research in this field for only four decades, Nagatitan is the 14th dinosaur to be named in the country. According to Palaeontologist Dr Sita Manitkoon from Mahasarakham University, the country has a high diversity of dinosaur fossils and is "possibly the third most abundant in Asia in terms of dinosaur remains."

This group originated around 140 million years ago, achieved a ⁠global distribution and, around 90 million years ago, became the only sauropods left worldwide, thriving until the dinosaur age ended 66 million years ago with an asteroid impact.

The Nagatitan roamed the planet when its atmospheric carbon dioxide levels were rising in line with increasing global temperatures. As per the study's co-author, UCL's Professor Paul Upchurch, the sauropod family of dinosaurs had become quite large at this time. "It seems a little odd that sauropods were able to cope with higher temperature conditions", as large bodies retain heat and are harder to cool down, he told National Geographic.

He told Reuters that it was likely that the high temperatures had an impact on the plant fodder that was important to sauropods, which were very large-bodied herbivores.

For prehistory enthusiasts, the discovery of Nagatitans is vital since it proves the existence of a unique evolutionary lineage called Euhelopodidae, which thrived independently due to the geographic barriers of the era. It also challenges the previous theories on the maximum size reached by herbivores in Southeast Asia during the mid-Cretaceous period.

A life-size reconstruction of Nagatitans is currently on display at Bangkok's Thainosaur Museum.