Highlights
- Nagatitan chaiyaphumensis measured 27 metres and weighed up to 28 tonnes.
- Villager's find in Chaiyaphum province led to largest regional dinosaur identification.
- Research links ancient temperature rise to massive dinosaur body sizes.
The fossils, found in Chaiyaphum province, include spine, rib, pelvis and leg bones.
Researchers recovered a humerus measuring 1.78 metres long, which helped them estimate the creature's body mass at 25 to 28 tonnes.
The dinosaur belonged to the sauropod group, known for long necks, long tails, small heads and four columnar legs.
"Nagatitan was probably a bulk browser that focused on consuming high volumes of vegetation that required little to no chewing such as conifers and possibly seed ferns," Thitiwoot Sethapanichsakul, a University College London doctoral student who led the research published in Scientific Reports, told Reuters.
Climate connection
The discovery shows how ancient environmental conditions influenced dinosaur growth. Nagatitan lived when Earth's atmospheric carbon dioxide levels were rising alongside high global temperatures.
Scientists found that sauropods grew particularly large during this time, with gigantic forms appearing across South America, China, North Africa and now southeast Asia.
"This possible relationship between large body size and high climatic temperatures is not fully understood, but it's likely that the high temperatures had an impact on the plant fodder that was important to sauropods," co-author Paul Upchurch, a University College London palaeontologist told Reuters.
At full size, Nagatitan faced few predation threats. The ecosystem's largest predator, a relative of Carcharodontosaurus, measured about eight metres long and weighed 3.5 tonnes.
Predators likely targeted only vulnerable juveniles or weakened adults rather than healthy specimens.
Nagatitan represents the 14th named dinosaur from Thailand and the youngest sauropod found in the region.
Scientists believe it may be southeast Asia's final titan, as the area became a shallow sea later in the Cretaceous Period.
