Newly Discovered Sauropod Is Biggest Ever Found in Southeast Asia at Likely 27 Tons, Nicknamed the “Last Titan”

A titanic long-necked dinosaur whose remains were discovered at a pond in Thailand may be among the last of its kind to show up in rock formations across Southeast Asia. This newly discovered dinosaur — named Nagatitan chaiyaphumensis — roamed along rivers between 100 million and 120 million years ago, and now claims the title of the largest known sauropod in Southeast Asia.

A new study published in Scientific Reports describes Nagatitan as the “last titan” of Thailand; the “titan” part of this name comes from the dinosaur’s colossal stature — it boasts an estimated body mass of around 27 tons, roughly equivalent to nine full-grown Asian elephants. But it’s specifically called the last titan because it was found in Thailand’s youngest dinosaur-bearing rock formation.

“I’ve always been a dinosaur kid,” said Thitiwoot (Perth) Sethapanichsakul, a Ph.D. student studying paleontology at the University College London, in a statement. “This study doesn’t just establish a new species but also [fulfills] a childhood promise of naming a dinosaur.”

Sauropod Discovery in Thailand

In the name Nagatitan, “Naga” refers to a mythological aquatic serpent featured in Southeast Asian folklore, while “titan” alludes to a group of giant deities in Greek mythology.

Researchers came across the bones of Nagatitan at the edge of a pond in north-eastern Thailand 10 years ago, recovering them from the Khok Kruat Mesozoic rock formation. They classified the dinosaur as a somphospondylan sauropod, a subgroup of sauropod (long-necked, plant-eating dinosaurs) that became widespread 120 million years ago. More specifically, it belongs to the Euhelopodidae family of sauropods, which are only found in Asia.

“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,” said Sethapanichsakul in the statement.

Read More: 125 Million-Year-Old Dinosaur Braincase Reveals How One Giant Predator Evolved

Growing Into a Giant

It was clear from the spine, rib, pelvis, and leg bones that Nagatitan was larger than life — one of its front leg bones alone was the size of a human, measuring in at around 5.8 feet long. The dinosaur’s whole body would’ve been almost 89 feet long.

Nagatitan lived during the Early Cretaceous, and according to Sethapanichsakul, it may have evolved to become so enormous from the increasingly arid and dry climatic conditions of the period. As global temperatures rose in the Early Cretaceous in response to elevated atmospheric CO2 levels, more savannah and scrubland environments began to expand throughout Southeast Asia. Sauropods like Nagatitan likely thrived in this kind of environment, easily able to shed heat from the surface area of their long necks.

While Sethapanichsakul says that a direct correlation between higher temperatures and the evolution of the largest body sizes in sauropods hasn’t been confirmed, super-gigantic sauropods from 100 million to 90 million years ago have been observed in several parts of the world. Millions of years before this pattern was solidified, Nagatitan may have emerged as an early case of growing to become supersized.

“Early Cretaceous Southeast Asia likely observed the beginning of these effects, which may have also driven Nagatitan to evolve to be so much larger than other sauropods, such as Phuwiangosaurus, that we know of from Southeast Asia that existed closer to the beginning of the Early Cretaceous (~130 million years ago),” Sethapanichsakul told Discover.

The Ongoing Search for Sauropods

Nagatitan lived in an area with a river system occupied by species of fish, freshwater sharks, and crocodiles. It also lived alongside smaller plant-eating iguanodontians and ceratopsians (cousins of the Triceratops), as well as large meat-eating spinosaurids and flying pterosaurs.

The Nagatitan bones examined in the new study might end up being the youngest giant sauropod remains in north-eastern Thailand, as rock formations younger than the Khok Kruat formation indicate that the area eventually became a shallow sea toward the final years of dinosaurs’ existence, and so they wouldn’t contain any dinosaur fossil remains.

Regardless, Sethapanichsakul says that more fossils of Nagatitan, or other undiscovered sauropods, may be out there.

“It is very much possible that we will find additional specimens of Nagatitan in the future,” Sethapanichsakul told Discover. “Excavation at the locality where the fossils were discovered is still ongoing and it is very possible that we may find even more fossils even if they do not belong to Nagatitan. We have also recently found very large sauropod remains that could potentially represent additional remains of Nagatitan in another province in Thailand.”

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