Along a winding river in what is now Thailand, around 113 million years ago, a gigantic herbivore roamed the land. This colossal creature, named Nagatitan chaiyaphumensis, was about 90 feet long, making it the largest known dinosaur from Southeast Asia.
Researchers discovered Nagatitan’s fossils after a villager stumbled upon them in the northeastern province of Chaiyaphum. Over several years, scientists unearthed many bones, including a humerus—an upper front leg bone—measuring nearly 6 feet long. This helped them estimate Nagatitan’s weight to be between 25 and 28 tons.
Thitiwoot Sethapanichsakul, a paleontology doctoral student from University College London, suggests that Nagatitan likely fed on large amounts of soft vegetation like conifers and possibly seed ferns. “Nagatitan was probably a bulk browser,” he noted. Since its head and teeth weren’t found, this assessment is based on what we know from related sauropods.
The climate during Nagatitan’s time likely included subtropical forests mixed with savanna-like areas, where it shared its habitat with various dinosaurs and flying reptiles like pterosaurs. Freshwater sharks and crocodiles populated the rivers nearby. The largest predator in this ecosystem was probably about 26 feet long, but it would have found little challenge in hunting such a massive creature.
Interestingly, healthy adult sauropods, due to their sheer size, were likely avoided by predators, though younger or sick individuals might have been targeted. Sethapanichsakul added that sauropods probably grew quickly to fend off predators—a trait that highlights their survival strategy.
Compared to some South American giants, Nagatitan isn’t the largest sauropod; species like Argentinosaurus and Patagotitan grew to over 100 feet. Its name references “Naga,” a serpent-like figure in some Asian cultures, hinting at its significance locally.
As the last of its kind in Southeast Asia, Nagatitan holds great importance for understanding the evolution of sauropods in the region. Its subgroup featured lighter bones with air sacs, which offered a unique advantage in movement and survival.
About 140 million years ago, this group began to spread globally, becoming dominant until the mass extinction event 66 million years ago. During its reign, the Earth was experiencing rising temperatures, potentially linked to higher carbon dioxide levels in the atmosphere. This correlation between size and climate is intriguing yet remains poorly understood. Paul Upchurch, a co-author of the study, noted that “the high temperatures may have influenced the plant life crucial for these gigantic herbivores.”
Nagatitan’s discovery adds valuable insight into the biodiversity of the time and the dynamics of prehistoric ecosystems. It illustrates how changes in climate and environment can affect life on Earth—even millions of years ago.
