Enormous dinosaur may be least scary thing to hail from Australia

The Australian dinosaur might descend from titanosaurs who trekked from South America through Antarctica, say paleontologists. 

First Look

Australian Age of Dinosaurs museum founder David Elliott was herding sheep when he came across a pile of bones in Western Queensland, Australia, in 2005. The discovery turned out to be huge – literally.

At first, Mr. Elliott thought that the bones might belong to a theropod like T. rex, but he was wrong. Instead, the bones belong to two enormous species of Titanosaur, massive long-necked creatures with a penchant for salad – perhaps actually much less frightening than a number of Australia's better-known creatures today, from scorpions, to saltwater crocodiles, to box jellyfish.

Once excavation began, paleontologists discovered bones from two distinct dinosaur species in the same rock formation. One, Diamantinasaurus matildae, featured skull fragments, a first for sauropods in Australia. The other, which Elliott and his wife Judy nicknamed Wade, belongs to a new species called Savannasaurus elliottorum.

In a study published in the journal Scientific Reports, researchers say that Wade can help scientists understand how dinosaurs made it to Australia in the first place.

“A new dinosaur like Wade, or Savannasaurus, will allow us to work out how these dinosaurs evolved through time, how they responded to climatic changes, and also how they responded to changes in the positions of the continents as well,” study lead author Stephen Poropat said in a video interview, according to the Los Angeles Times.

Titanosaurs have been discovered around the world, but experts say Wade is most similar to titanosaur species discovered in South America.

During the early part of the dinosaur era, present-day South America and Australia were both part of a supercontinent called Pangaea, but by the time Wade made Australia his home, about 95 million years ago, the modern continents had separated. So how did Wade come to live Down Under?

After comparing Wade to South American titanosaurs, and considering what they knew about the position of the continents at the time, paleontologists determined that titanosaurs may have crossed to Australia via Antarctica, a route made more accessible by prehistoric global warming. (Antarctica hadn't yet reached the South Pole, but it was already at high latitudes.)

"One of the most exciting things about this discovery – and others that have come from Australia in recent years – is we’ve really only scratched the surface as to what’s there," Carnegie Museum of Natural History curator Matthew Lamanna told the Verge. "There are entire lost worlds of dinosaurs waiting to be found in Australia."

In some ways, S. elliottorum was the cow of the dinosaur world. Wade had wider hips and a bigger belly than most titanosaurs, which helped him digest fibrous plants and trees.

“If you’re going to be digesting tough plant matter,” Dr. Poropat told the Washington Post, “the bigger the better.”

Digestion matters for creatures as large as Wade, whose impressive length rivals that of a tractor trailer. Weighing in at 40,000 pounds and measuring approximately 50 feet, S. elliottorum would have been a sight to behold.

Although Wade and his fellow titanosaurs are continuing to provide clues, researchers write, “considerable further work is required before the complex biogeographic history of the Australian Cretaceous terrestrial vertebrate fauna can be unraveled.”