Sita Manitkoon oversaw the recovery of Nagatitan, the largest dinosaur ever discovered in Thailand.
Tanintorn Ketburana
Colossal Cretaceous sauropods
Nagatitan left behind a smattering of vertebrae, ribs, hip bones, and limb bones entombed in 113-million-year-old rock. Its right forelimb is longer than that of other, recently uncovered giant sauropods such as Patagotitan and Dreadnoughtus, though the dinosaur itself likely was not as big as those heavy hitters, which weighed an estimated 60 and 50 tons respectively.
The largest dinosaurs of all time were not each other’s closest relatives. Sauropod dinosaurs evolved their giant body sizes more than 30 times over the course of more than a hundred million years on at least six landmasses. Nagatitan became a giant independently of other huge dinosaurs from other periods and places, but its relationships and habitat suggest it lived at the beginning of a time conducive to enormous dinosaurs.
Nagatitan belonged to a group called the somphospondyli. These dinosaurs tend to have long forelimbs compared to other sauropods, as well as a wide stance, says Paul Upchurch, a paleontologist at the University College London and a coauthor of the study. The other differences would have been difficult to spot on the living animal, but these subtle cues identify the Nagatitans as a group of immense dinosaurs that spread far and wide some 110 to 120 million years ago during the Early Cretaceous.
Sita Manitkoon and the Thai Paleontology Youth Network recovered a dorsal rib (about six feet long) from the site and moved it to the Sirindhorn Dinosaur Museum.
Tanintorn Ketburana
How titans thrived
Environmental conditions in Cretaceous Thailand might explain why Nagatitan was so large.
During the time the dinosaur lived, Thailand was closer to the equator than it is today. Clues found in the same formation in which Nagatitan was buried indicate that the region was covered by relatively open, slightly dry shrublands. Earth was in a hothouse state, and recent research has suggested that big sauropod dinosaurs thrived under such conditions. Humongous herbivores could easily and efficiently travel through the woodlands, browsing on trees and nibbling plants like horsetails and ferns down low. Their feeding and trampling of the soils also kept such habitats more open and savanna-like rather than thickly forested.
