Prehistoric Titan: In Thailand, paleontologists have discovered the fossil of the largest long-necked dinosaur in Southeast Asia. The sauropod named “Nagatitan” was 27 meters long and weighed 27 tons – it weighed as much as nine adult Asian elephants. The gigantic herbivore lived around 110 to 120 million years ago, making it one of the youngest dinosaurs in Thailand. It was a close relative of the European titan, which occurred almost simultaneously on the Iberian Peninsula.
Whether Australotitan, Argentinosaurus or Dreadnoughtus: The titanosaurs are among the largest and heaviest land animals that have ever lived on earth. Typical of these dinosaurs, which were often more than 20 meters long and weighed up to 60 tons, was a massive, barrel-shaped body with a long tail and neck as well as a small head. Like all sauropods, titanosaurs were herbivores. They occurred from the late Jurassic period around 150 million years ago to the end of the Cretaceous period and were widespread almost worldwide.
27 meters long and weighs 27 tons
Now there is a new addition to the prehistoric titans: Nagatitan chaiyaphumensis. The 100 to 120 million year old fossils of this new species of titanosaur were found around ten years ago on the edge of a pond in northeastern Thailand. Among them were vertebral bones, ribs, hip bones and some leg bones, including the dinosaur’s 1.78 meter long femur. Initial investigations suggested that these must be the bones of a large sauropod.
Now paleontologists led by Thitiwoot Sethapanichsakul from University College London have completed the analysis of this fossil. Accordingly, the Nagatitan was around 27 meters long and weighed around 27 tons during its lifetime. “This makes Nagatitan currently the largest known titanosaur in Southeast Asia,” report the paleontologists. They suspect that these dinosaurs benefited from a rise in temperatures in the Early Cretaceous and the change in landscape from rainforest to savannah. As a result, the titanosaurs increased in size compared to their older relatives.
“The Last Titan of Thailand”
The newly discovered Nagatitan lived in an area where a meandering river crossed the semi-arid savanna landscape. The river provided enough water for the vegetation and thus the food of the gigantic sauropod, and at the same time it was a habitat for fish, crocodiles and freshwater sharks, as other fossil finds reveal. However, this landscape did not last long: in the Late Cretaceous the sea flooded this region.
“That’s why we call the Nagatitan the last titan of Thailand,” says Sethapanichsakul. “Its fossils were discovered in the youngest rock formation in the country that still contains dinosaur relics. Nagatitan could therefore be the last or youngest large sauropod to live in what was then Southeast Asia.” However, many dinosaur fossils found in Southeast Asia and Thailand have not yet been examined and described in more detail, as the researcher explains. In this respect, further new discoveries cannot be ruled out.
Sister group of the European titan?
The family tree position of the newly discovered Nagatitan is also interesting: Based on its characteristics, Sethapanichsakul and his colleagues assign it to the Euhelopodidae, a titanosaur family that is currently only known from Asia. At the same time, however, the Nagatitan also resembles the European Titan in some features, whose fossils were discovered in Spain a few years ago. “The results of our phylogenetic analyzes show Nagatitan as a sister taxon to Europatitan,” write the paleontologists.
If this is confirmed, it will shed new light on the family tree position of the European titan and also the Asian titanosaurs. “Europatitan would be the first euhelopodid from outside Asia,” explain Sethapanichsakul and his team. As a result, this group of titanosaurs would not be a purely Asian development – contrary to long-standing assumptions. And the classification of the European titan would then have to be revised again.
However, the researchers also emphasize that there are anatomical differences between Europatitan and Nagatitan, which call into question the assignment of Europatitan to the Euhelopodidae. “We therefore consider it premature to assume that these titanosaurs are present outside of Asia,” they write.
Source: Thitiwoot Sethapanichsakul (University College London) et al., Scientific Reports, 2026; doi: 10.1038/s41598-026-47482-x