Paleontologists have officially identified a massive, brand-new species of long-necked dinosaur in Thailand, crowning it the largest dinosaur ever discovered in Southeast Asia.

The newly described titan, named Nagatitan chaiyaphumensis, roamed the warm, arid floodplains of what is now northeastern Thailand roughly 113 million years ago during the Early Cretaceous period.

The groundbreaking research, published in the journal Scientific Reports, reveals that this ancient plant-eater reached a staggering 27 meters (89 feet) in length and weighed an estimated 27 tonnes—the equivalent of nine adult Asian elephants.

Unearthing the Naga Titan

The initial discovery dates back a decade when a local villager spotted fossilized bones at the edge of a pond in Thailand’s Chaiyaphum province. Over a multi-year excavation process completed in 2024, an international team of scientists from University College London (UCL), Mahasarakham University, Suranaree University of Technology, and the Sirindhorn Museum meticulously uncovered a treasure trove of skeletal remains, including the spine, ribs, pelvis, and leg bones.

Among the most extraordinary fossils recovered was a front leg bone (the humerus) measuring 1.78 meters (5.8 feet) long—matching the height of an average human.

The genus name Nagatitan honors the "Naga," a mythological, water-associated serpent creature central to Thai and Southeast Asian folklore, combined with "Titan," the giants of Greek mythology. The species name, chaiyaphumensis, roots the beast to the province where it lay buried for over a hundred million years.

"The Last Titan" of an Ancient Ecosystem

Nagatitan belongs to the sauropod lineage—the famous four-legged, long-necked, long-tailed herbivores that include Diplodocus and Brontosaurus. Lead author Thitiwoot (Perth) Sethapanichsakul, a Thai PhD student at UCL, has affectionately dubbed the creature "the last titan" of Thailand.

According to Sethapanichsakul, 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. Therefore, this may be the last or most recent large sauropod scientists will find in Southeast Asia.

Though its head and teeth weren't recovered, anatomical comparisons with more than 150 other species place Nagatitan within the Euhelopodidae family—a distinct subgroup of somphospondylan sauropods entirely unique to Asia. Paleontologists believe it was a bulk browser, utilizing its massive size to consume high volumes of vegetation like conifers and seed ferns without the need for intensive chewing.

Living Among Apex Predators

During the Cretaceous Period, northeastern Thailand featured a subtropical landscape woven with meandering river systems. Rivers teemed with prehistoric fish, freshwater sharks, and ancient crocodiles, while flying pterosaurs patrolled the skies.

On land, Nagatitan shared its environment with smaller herbivorous dinosaurs like iguanodontians and early ceratopsians. It also shared the land with terrifying apex predators, including an 8-meter-long (26-foot) relative of Carcharodontosaurus weighing 3.5 tons.

However, at full size, Nagatitan was so structurally massive that it effectively outgrew the threat of predation. Healthy adults had very little to fear from the region's meat-eaters, who likely avoided them entirely to escape being stepped on or crushed.

Climate and the Evolution of Giants

The discovery sheds crucial light on how ancient climate conditions drove the evolution of mega-species. Co-author Professor Paul Upchurch (UCL) noted that Nagatitan lived during an era when global temperatures and atmospheric carbon dioxide levels were climbing rapidly.

This climate shift drastically altered the period's plant life, supercharging the growth of high-abundance vegetation. Sauropods across the globe—in South America, China, and now Southeast Asia—simultaneously evolved massive body sizes to capitalize on this lush plant fodder, offering an incredible glimpse into a world of true titans.

References

• Primary Study: Sethapanichsakul, T., Upchurch, P., Manitkoon, S., et al. "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). doi:10.1038/s41598-026-47482-x.

• Secondary Report: "New species of giant dinosaur identified from remains found in Thailand," CNN Science.