Dinosaurs Crossed Continents Through Nearly 100-million-year-old Land Bridge in Antarctica, Study Finds

The close-to-complete skull fossils of a sauropod spotted in Australia strikingly resemble fossils found in South America. This suggests that dinosaurs crossed continents through Antarctica back when it was still free of ice.

Close-to-complete D. Matildae Skull Found in Australia

Live Science reports that the first-ever close-to-complete skull is part of the dinosaur species known as Diamantinasuarus matildae. With their necks stretching even farther than a school bus, it is no surprise that sauropods are known for their long necks.

D. matildae was also considered a titanosaur, which is the only sauropod group to reach the Cretaceous end. This was before the extinction of nonavian dinosaurs.

The specimen was excavated in 2018 on a sheep ranch in Queensland, Australia. It has since been dubbed "Ann." The length of the creature, D. matildae, is equivalent to a tennis court, while its weight went as high as 27.5 tons.

Researchers from Curtin University examined the close-to-complete skull, which enabled them to know more about the creature's anatomy, feeding habits, and social relationships. Moreover, they found resemblances between these fossils and ones spotted elsewhere.

How Dinosaurs Crossed Continents

The recent study was published in the Royal Society Open Science publication.

In a 2016 study, researchers discovered resemblances between the skulls of Ann and the Sarmientosaurus musacchioi titanosaur. Such similarities include braincase details.

While researchers already guessed the link shared by these two species, they lacked evidence to support their claims. However, this new skull now backs it up, as the two are very similar "bone for bone."

With these new findings, they thus support the theory that sauropods traveled to and from Australia and South America back in the mid-Cretaceous.

Back then, Antarctica was still filled with vegetation and forests. Scientists were already familiar with how sauropods used to loom over such areas, as the first fossil of a long-necked dinosaur in Antarctica was found in 2011.

The window from 100 to 95 million years ago was one of the warmest that the earth faced in its "geologically recent history." This meant that the presently icy Antarctica was not filled with ice back then. Australia, on the other hand, was much further south compared to where it is today. It was also much warmer and had less seasonality.

In such climates, Antarctica was filled with forests and could have been an ideal pathway or habitat for sauropods.

Matthew Lamanna, a co-author of the 2016 study and a paleontologist from the Carnegie Museum of Natural History, notes how detailed and packed the study is. Lamanna adds that the striking resemblances further support the hypothesis that titanosaurs moved between South America and Australia back in the mid-Cretaceous and that they may have moved by passing through Antarctica.

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