A single front leg bone nearly six feet long. A partial skeleton scattered across a dry pond bed in northeastern Thailand. From these fragments, researchers have reconstructed a creature that stretched roughly 27 metres from nose to tail — the largest dinosaur ever found in Southeast Asia.

Meet Nagatitan chaiyaphumensis. The name borrows from the Naga, the serpent deity revered across Southeast Asian traditions, and the Greek “titan,” which needs no explanation. The species epithet honours Chaiyaphum Province, where a local resident first spotted the fossils exposed by low water levels in 2016.

Research published Thursday in the journal Scientific Reports estimates the sauropod weighed 25 to 28 tonnes and browsed treetops roughly 113 million years ago, during the late Early Cretaceous. Based on recovered spine, rib, pelvis, and leg bones — no skull or teeth were found — the team placed Nagatitan among the somphospondylan titanosauriforms, a group of long-necked herbivores whose air-filled bones lightened enormous frames.

Thitiwoot Sethapanichsakul, a University College London doctoral student and lead author, described the find as an evolutionary “on-ramp” — not quite the 70-tonne giants that appeared later in South America and China, but a clear step in that direction. Rising global temperatures during this period may have driven the trend by expanding habitat and boosting plant growth, according to study co-author Paul Upchurch.

Nagatitan is the 14th named dinosaur from Thailand and likely the last large one. The Khok Kruat Formation that preserved it is the country’s youngest dinosaur-bearing rock layer; after this, the region was swallowed by shallow seas.

Paleontologist Mathew Wedel, who was not involved in the study, put the significance plainly: “Every country gives us a new window into a little bit different part of the past.”

That window, in this case, frames a very large creature indeed.

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