How did dinosaurs become so enormous? Giant new dinosaur found in Thailand could answer the frequently asked question

This has been one of the most enduring FAQs: Back in their days, how exactly did dinosaurs get so big? What’s their origin story in reference to their size?After years of pondering on this question, it seems like researchers finally have a clue about the answer to it.Scientists in Thailand have dug up a massive new dinosaur species, Nagatitan chaiyaphumensis, and it’s shaking up what we know about why dinosaurs got so big. Per National Geographic, this dinosaur is officially the largest ever discovered in Southeast Asia, coming in at nearly 90 feet long and weighing as much as nine elephants. And its sheer size isn’t the only thing turning heads; researchers think it could help crack the case on what triggered the rise of those gigantic plant-eaters millions of years ago.Here’s how the story goes: A local man, Thanom Luangnan, spotted some weird rocks beside a pond in Chaiyaphum Province back in 2016. Turns out, those “rocks” were dinosaur bones, and they were huge. Over several years, scientists pulled out vertebrae, ribs, pieces of the pelvis, and an enormous leg bone, all tucked away in 113-million-year-old rock.One leg bone in particular blew everyone away. It was 1.78 meters long, which is nearly the height of the average adult. The dinosaur overall stretched about 27 meters from head to tail.The name Nagatitan mixes a bit of mythology and geography: “Naga” from serpent legends of the region, “Titan” borrowed from the Greek, and “chaiyaphumensis” marking the local province.In a journal article, scientists explained that Nagatitan belongs to somphospondylans, think distant cousins of the famous titanosaur giants that once roamed South America and Asia.Back when Nagatitan lived, Earth was going through a greenhouse phase: warmer temperatures, high CO2, and Southeast Asia was practically on the equator. The land was open woodland and savanna, full of ferns and conifers. That’s paradise for big plant-eaters, with lots of space and food.Picture a buffet that never runs out. In wide, open areas, giant sauropods could wander freely and eat nonstop. They kept the landscape open at the same time, a bit like modern elephants shaping their environment.“This is the most complete sauropod we’ve ever found in the Khok Kruat rocks,” National Geographic quoted paleontologist Pedro Mocho as saying. Usually, Southeast Asian dinosaur finds are just scattered bones, so this one fills in big gaps.Another surprise: Researchers now believe enormous size didn’t evolve just once in dinosaurs. It happened over and over with giant sauropods like Nagatitan that popped up on different continents, evolving more than 30 times separately.Now, Nagatitan’s timing is important. It lived at the beginning of a stretch when Asian sauropods started to get seriously big. Later, relatives like Ruyangosaurus in China grew even heavier, maybe tipping 60 tonnes. Studying Nagatitan helps scientists track the evolutionary path of these giants across ancient Asia.How did these monsters survive the heat? You’d think a massive animal would struggle to cool off. Turns out, sauropods came with a few tricks: long necks for more surface area (better at losing heat), and light, air-filled bones that doubled as cooling and made supporting all that weight manageable.However, none of this would matter much, except for one thing: Southeast Asia hasn’t had nearly as many dinosaur discoveries as somewhere like North America or China. Finds like Nagatitan are changing the story, showing that the age of titans stretched further than we once thought.