New Australian herbivorous dinosaurs found 15 meters long and weighed nearly 20 tons

Archaeologists say they have discovered a new dinosaur in Australia. They have wide hips, long necks, walk on four feet, eat grass and are half the length of a basketball court. The fossil dinosaurs found in Australia are extremely rare, and this finding could help scientists gain insight into where these giant creatures once lived on our planet from millions of years ago.

David Elliott, head of the Australian Ancient Dinosaur Museum, accidentally discovered the fossil of the dinosaurs in 2005. At that time, while shepherding sheep in the town of Winton in northern Australia, he had discovered what he initially thought was bone fossil chi. When his wife, Judy Elliott, put two of the fossil pieces together, they found that it was a giant toe bone, a herbivorous dinosaur. Observing the rest of the bone, the archaeologist found it belongs to a completely new dinosaur belonging to a group of herbivorous dinosaurs called Sauropoda (Lizard foot dinosaurs).

Graphic depicting Savannasaurus elliottorum dinosaurs based on fossils obtained.

Now, after more than 10 years of work, a team of scientists led by Australian archaeologist Stephen Poropat has officially published their findings in Scientific Reports. They named the dinosaur Savannasaurus elliottorum , inspired by the Elliott family and the grassy area where they discovered it. This is an important finding, according to Matthew Lamanna, who is in charge of the vertebrate ancient group at the Carnegie Museum of Natural History in Pennsylvania (USA), who is not involved in the study. "Dinosaurs from Australia are extremely rare, and most Australian dinosaurs are envisioned by very few fossil samples, " he said.

In contrast, Savannasaurus is one of the most complete sauropods ever discovered in Australia. Based on its skeleton, scientists estimate it to be about 15 meters long, with a long neck and a round, wide body, weighing nearly 20 tons, equivalent to the weight of three African elephants. Plus, Poropat said. The researchers did not find fossil or dental feces to determine what Savannasaurus once ate, but at such a size, it could be predicted that they had a low-quality grass diet. That may be why this dinosaur has a wide hips, because it needs a very long intestinal tract to extract nutrients from fibrous food.

Savannasaurus lived in Australia from 95 to 98 million years ago along with two other Titanosaurs . This corresponds to the end of the Cretaceous period, the last part of the dinosaur era beginning about 225 million years ago and ending when an asteroid hit the Earth at a time of 66 million years ago, leading to the extinction of the giant animal that once dominated this planet. We still don't know how the dinosaurs moved to Australia, but during this time, the Australian continent was connected to South America, through Antarctica, before the Earth warmed. It is also possible that this reptile used to live there, but their bones existed not long enough to be found.

David Elliott is holding a one-toe bone of Savannasaurus elliottorum.

In his article, Poropat and his colleagues also published their findings about the skull of another Australia's lizards, Diamantinasaurus matildae . This species was discovered in 2009, but the discovery of Diamantinasaurus' first skull was truly significant because it could help scientists place Diamantinasaurus in a more precise position in the dinosaur genealogy.

Currently, Poropat and his colleagues suspect that Savannasaurus and Diamantinasaurus may have some close ties. While researchers believe they are two separate species, archaeologists will need to find more fossils to confirm that.

"Whenever you give a dinosaur a name, that's just a hypothesis, so it still needs to be tested and verified in the future , " Poropat said. "One of the most interesting things about this discovery, as well as other discoveries from Australia in recent years - is that we have only touched a very small part of what used to be there" , Lamanna said. "There's a whole world of dinosaurs lost in Australia and waiting for us to seek."