Thailand's 'Last Titan': How Strange Rocks by a Pond Became Southeast Asia's Largest Dinosaur

In 2016, a resident of Thailand's Chaiyaphum province named Thanom Luangnan noticed something odd poking out of the ground beside a public pond. The lumps looked like rocks, but their shapes were too regular. He reported them to the Department of Mineral Resources, and paleontologists who came to investigate confirmed what he had stumbled upon: fossilised bones of an enormous dinosaur. Nearly a decade later, on 14 May 2026, that animal was formally named in the journal Scientific Reports as Nagatitan chaiyaphumensis.

The work was anything but quick. According to the Smithsonian magazine account, the first excavation in 2016 recovered roughly ten bones, but funding lapsed in 2020. Fieldwork only resumed in 2023 with support from the National Geographic Society, letting the team finish describing the specimen. Thailand has produced just a handful of named dinosaurs, and formal study there began only about four decades ago, so each new find meaningfully expands the record.

The name fuses the Naga, a serpent of Thai and wider Southeast Asian mythology, with the Greek Titan; the species name honours the province where it was found. According to Sci.News, it is the 14th dinosaur species formally named from Thailand, where the scientific hunt for dinosaurs began only in the 1980s.

What is a sauropod, and what kind was this?

Sauropods were the long-necked, long-tailed, plant-eating giants of the dinosaur world, walking on four pillar-like legs. The largest sauropods are the biggest land animals ever known to have existed. Nagatitan belonged to a more specific group, the somphospondylans, and within that to the Euhelopodidae, a family found only in Asia. These titanosauriforms had relatively long forelimbs and a wide stance. As paleontologist Paul Upchurch of University College London told National Geographic, the combination of elongated necks and air-sac-filled bones helped such animals "balloon in size" when conditions allowed.

That body plan was a feat of biological engineering. A long neck let a sauropod sweep across a wide arc of vegetation without moving its bulk, while a system of air sacs threaded through the bones lightened the skeleton and likely helped the animal shed heat. Those same air-filled bones, however, are fragile, which is part of why complete sauropod skeletons are so rare and why finds like Nagatitan usually arrive as scattered fragments.

The team that described it came from University College London, Mahasarakham University, Suranaree University of Technology and Thailand's Sirindhorn Museum, led by UCL doctoral researcher Thitiwoot Sethapanichsakul.

How big was it — and how do we know?

Researchers estimate Nagatitan stretched roughly 27 metres long and weighed around 27 tonnes — comparable in length to a modern blue whale, and several times the mass of a Tyrannosaurus rex, which is typically estimated near 8 tonnes. ScienceDaily reports the figures at about 27 tonnes; Sci.News cites a range of 25 to 28 tonnes. Lead author Sethapanichsakul noted it likely outweighed "Dippy the Diplodocus" by at least 10 tonnes.

Such numbers should be read as estimates, not measurements. The skeleton is partial — vertebrae, ribs, parts of the pelvis and limb bones, including a leg bone measuring 1.78 metres. To estimate total length and mass, paleontologists scale up from these fragments using the proportions of better-known relatives, so different methods can yield different figures. What impressed the team was the forelimb: National Geographic reports its right forelimb exceeded those of the South American giants Patagotitan and Dreadnoughtus, even though Nagatitan itself was the smaller animal overall.

Why it matters for Asian dinosaur diversity

Co-author Sita Manitkoon of Mahasarakham University said initial measurements suggested "this could be the largest dinosaur ever found in Southeast Asia" — a claim the team frames carefully given the incomplete skeleton. The animal lived during the late Early Cretaceous, the Aptian–Albian stages, roughly 100 to 120 million years ago (about 113 million years), in the Khok Kruat Formation.

The find adds to a growing picture of Asian sauropod evolution. Researchers suggest Nagatitan was part of a mid-Cretaceous trend toward larger body sizes in Asian titanosauriforms, possibly aided by warming temperatures and expanding suitable habitat. Even larger Asian relatives, such as Ruyangosaurus, later approached 50 to 60 tonnes. Such giants evolved independently more than once across the dinosaur era and on multiple continents, and the Thai fossil hints that Southeast Asia hosted its own chapter of that story — one only now coming into focus.

The 'last titan'

The team nicknamed Nagatitan "the last titan" of Thailand because it comes from the country's youngest dinosaur-bearing rock layer. Younger formations in the region lack dinosaur fossils: by the Late Cretaceous, much of the area had become a shallow sea. That marine transgression may mean Nagatitan was among the last giant sauropods to roam this part of Southeast Asia before rising waters reshaped the landscape. As Sethapanichsakul put it to Smithsonian magazine and others, his aim is to get Southeast Asian dinosaurs the international recognition they have long lacked — a recognition that started, in this case, with a sharp-eyed villager and some strange-looking rocks.