Colossal 88-foot dinosaur discovered in Thailand was region's largest

A colossal dinosaur, designated Nagatitan chaiyaphumensis, once traversed South-East Asia approximately 120 million years ago, measuring an staggering 88 feet in length and weighing 27 tonnes. This discovery confirms the existence of a sauropod three times the size of a modern London bus, marking it as the largest dinosaur ever identified in the region. The creature's immense mass, equivalent to that of nine adult Asian elephants, suggests it functioned as a mega-herbivore capable of browsing high treetops with minimal fear of predation.

The fossil record was established through the painstaking excavation of skeletal remains, including vertebrae, ribs, a pelvis, and a front leg bone comparable in size to a human. These fragments were initially discovered a decade ago by a local resident near a pond in Chaiyaphum, a province in northern Thailand. Co-author Thitwoot Sethapanichsakul, a PhD student at University College London, noted that the animal likely consumed vast quantities of vegetation requiring little chewing, a feeding strategy common among its kin.

Between 100 and 120 million years ago, the geography of what is now Thailand differed significantly from its current state. Rather than the humid, sub-tropical climate seen today, the landscape was characterized by arid conditions featuring a mix of forests, savanna-like terrain, and shrublands. The specific site of discovery lay within a meandering river system that supported diverse life, including fish, freshwater sharks, and crocodiles. Despite the presence of formidable predators such as relatives of the Spinosaurus and the giant Carcharodontosaurus, the sheer scale of the Nagatitan would have dwarfed these carnivores, which reached lengths of only 26 feet and weights of approximately 3.5 tons.

The environment presented unique challenges, particularly the intense seasonal dryness, yet sauropods like Nagatitan thrived under such conditions. As global temperatures rose during a natural warming phase between 115 and 95 million years ago, accompanied by elevated CO2 levels, these giants utilized the massive surface area of their necks and tails to regulate their body heat. Professor Paul Upchurch, another co-author from University College London, highlighted that the animal's physiology allowed it to adapt effectively to these shifting climatic pressures. This research underscores the limited nature of current fossil data, as the full extent of this species' history remains accessible only through these specific, privileged archaeological findings.

New fossil evidence reveals Nagatitan, a massive sauropod dinosaur that roamed Thailand around 95 million years ago. Lead researcher Thitiwoot Sethapanichsakul notes this discovery links to a significant increase in sauropod body size during that era.

"We see super gigantic 70 metric tonne forms living around 95 million years ago," says Mr Sethapanichsakul. This growth allowed these creatures to become the most successful and widespread species of the Early Cretaceous period.

Although the exact biological connection remains not fully understood, Nagatitan offers a rare glimpse into these early evolutionary stages. Even while dominating its local habitat, it would have looked relatively puny compared to other giants of the time.

"When compared to other sauropods, it ranks in the upper middle of the size range," Mr Sethapanichsakul explains. True super giants emerged in the middle Cretaceous across South America, China, and likely North Africa. Those massive forms exceeded 60 tonnes in body mass.

From the outside, Nagatitan resembled its larger cousins with a long neck, long tail, column-like legs, and a tiny head. However, scientists identified unique characteristics in its legs, hips, and spine that confirm it as a distinct species.

Based on teeth and scales, scientists believe Nagatitan shared its environment with fish, crocodiles, sharks, and other dinosaurs. Yet, this giant would have dwarfed them all.

Nagatitan belonged to a subgroup of sauropods possessing bones with internal air sacs and thin walls. These features made their skeletons significantly lighter. This group appeared about 140 million years ago and spread globally.

Around 90 million years ago, they became the only sauropods remaining worldwide. They held this position until the dinosaur age ended 66 million years ago. Its scientific name, Nagatitan chaiyaphumensis, references the 'Naga,' a mythological serpent from South-East Asian mythology often connected with water.

"Its specific name of chaiyaphumensis pays homage to the fact that the fossils were found in Chaiyaphum province, Thailand," says Mr Sethapanichsakul. The moniker 'titan' refers simply to the dinosaur's enormous size. Researchers now call it Southeast Asia's last 'titan.'

Sometime after this specimen lived, Thailand was submerged by a shallow sea. This event may have driven the dinosaurs out. Professor Upchurch adds, "Although animals like this continue to live elsewhere in the world, it may be that large portions of Southeast Asia were flooded by sea level rise afterwards."

"So it might not have been possible for these animals to have lived there much after the time of Nagatitan," he concludes.