Massive dinosaurs seems like the norm, but they weren't always giants. However, a newly discovered fossil suggests gigantism in dinosaurs evolved earlier than previously believed.
For years, scientists say that dinosaurs developed gigantism when sauropods, known as the largest animals to ever exist in the planet, first emerged during the Jurassic period that occurred 200 to 145 million years ago.
Now, new research says that gigantic sauropodomorphs actually came on the scene much earlier, during the Triassic period around 215 million years ago.
Researchers Find The First Giant From The Triassic
In the study published in the journal Nature Ecology & Evolution, researchers discovered that the new species that was recently unearthed was a sauropodomorph that lived 215 million years ago — a shocking 30 million years before related giants such as Brachiosaurus and Diplodocus walked the Earth.
The creature, named Ingentia prima or "first giant" in Latin, was found with three other related dinosaurs in the northwest region of Argentina. It weighed 10 tonnes (over 22,000 pounds) with a neck 10 meters (over 32 feet) long, which may not be as heavy or large as later species, but was unprecedented in that era.
In an analysis in BBC News, Dr. Steve Brusatte of the University of Edinburgh in Scotland explains that it used to be widely accepted that giants first lived after a supervolcano caused global extinction in the end of Triassic. The new study, he explains, proves that there were sauropods called lessemsaurids who not only grew to gigantic sizes before the mass extinction but also evolved indepedently of its more popular four-legged cousins.
"The development of huge size wasn't just a one-off event for the sauropods, but rather different types of dinosaurs were able to become colossal, which speaks to just how incredible these animals were," Brusatte wrote in BBC.
The Dinosaurs That Grew To Be Giants
There are differences, but this new dinosaur shared similar traits with later sauropods as well including bird-like air sacs that could have helped the gigantic creatures stay cool.
The recovered bones show growth rings that indicate rapid growth.
"We could observe in the bones [from the growth rings] that they had markedly high-growth periods," study coauthor Dr. Cecilia Apaldetti of Universidad Nacional de San Juan in Argentina notes in BBC.
Furthermore, Live Science points out that scientists used to believe that super-sized dinosaurs required straight legs, since straight legs offer more support as they become larger and larger. However, lessemsaurids walk on bent legs, but as Apaldetti and the rest of the team discovered, their bones grew in spurts.