Australotitan

*Australotitan cooperensis*

*Australotitan* is a genus of titanosaur sauropod dinosaur that lived during Early Cretaceous Queensland, Australia, approximately 92-96 million years ago.

The ancient giant belongs to Titanosauria, a diverse group of sauropod dinosaurs known for containing some of the largest creatures to walk the earth.

## Discovery and naming

   *Australotitan* was discovered in 2005 within the Winton Formation of southwest Queensland, Australia, near the town of Eromanga. Sandy Mackenzie, the discoverer, had already collected other bones on the land of his parents in 2004. The fossil material was then prepared and excavated in conjunction with the Queensland Museum and the Eromanga Natural History Museum between November 2005 and April 2010. It was nicknamed "Cooper" after its discovery being from the Cooper-Eromanga Basin, Cooper Creek system, ‘the Cooper Country”. The holotype, **EMF102** (nicknamed "Cooper"), was described in 2021 on the basis of a partial skeleton consisting of a partial left scapula, partial left and complete right humeri, right ulna, the right and left pubes and ischia, and partial right and left femora. An additional three specimens were referred to the genus: **EMF164**, nicknamed "George," (fragmented femur, ulna, presacral vertebrae, and rib material), **EMF105**(a complete femur), and **EMF165** (a distal humerus). Several of the fossils found and worked on at Eromanga Natural History Museum are seen to have been trampled and compressed during deposition. This was the result of multiple smaller sauropods walking in a single line. The trackway has a total length of approximately 100 metres (330 ft). The type species, *A. cooperensis,* was named and described by Scott A. Hocknull, Melville Wilkinson, Rochelle A. Lawrence, Vladislav Konstantinov, Stuart Mackenzie and Robyn Mackenzie in 2021. The generic name, *Australotitan*, combines the Latin word "australis," meaning "southern," as it was found in Australia (which is sometimes referred to as "The Great *Southern* Land"), with the Greek word "Tιτάν" meaning "titan", in reference to the Greek mythological Titans and the dinosaur's gigantic size. The specific name, *cooperensis*, refers to the Cooper Creeksystem near the initial location of the holotype, and the nickname given to the holotype when it was discovered.

*In the early 2000s, Australia was at the beginning of a dinosaur-rush, with a number of significant new species of dinosaurs and megafauna being discovered in the past 20 years.* quoted by Dr. Jim Thompson, CEO of Queensland Museum Network. He added: *Australia is one of the last frontiers for dinosaur discovery and Queensland is quickly cementing itself as the paleo-capital of the nation — there is still plenty more to discover.*

*Australotitan cooperensis* adds to the growing list of uniquely Australian dinosaur species discovered in Outback Queensland, and just as importantly showcases a totally new area for dinosaur discovery in Australia,” said Dr. Scott Hocknull, a researcher at the Queensland Museum and the University of Melbourne.

## Description

*Australotitan* represents the largest known Australian dinosaur. The thighbone of specimen EMF164 has a length of 2.146 metres (7.04 ft), similar in size to the femora of *Futalognkosaurus* and *Dreadnoughtus*, though smaller than those of *Patagotitan*. The describing authors deliberately abstained from providing a size estimate, as it is notoriously difficult to obtain reliable results for sauropods. The discovery of *Australotitan* indicates that the gigantic titanosaurian sauropods were present during the mid-Cretaceous of eastern Gondwana.

*Australotitan* is the largest sauropod from Australia, recovered from a locality estimated 270-300 meters from the Winton Formation's base. Based on osteological remains and limb sizes, *Australotitan* compares in size titanosaur from South America. The taxon was differentiated based on 3D surface scans and comparisons to *Diamantinasaurus*, *Wintonotitan* and *Savannasaurus*.

The authors also criticized sauropod studies in the naming paper, stating specimens are difficult to compare. To overcome this, they used 3D cybertypes and colour reference schemes.

## Classification

In a phylogenetic analysis performed by Hocknull *et al.,* *Australotitan* was recovered as a titanosaur. In eleven out of fourteen analyses, it was placed in a clade with the contemporaneous Titanosaur *Diamantinasaurus*, which, depending on the dataset, also included other Winton FormationSauropods *Wintonotitan* and *Savannasaurus*, and sometimes also *Sarmientosaurus*, *Baotianmansaurus*, *Dongyangosaurus*, *Erketu*, and *Pitekunsaurus*. This places it in the clade Diamantinasauria sensu Poropat *et al.* (2021).

## Paleobiology

*A. cooperensis* was between 25-30 m (82-98 feet) long, 5 and 6.5 m (16.4-21.3 feet) high, and had a mass between 23 and 74 tons.

The large sauropod was, like the rest of its family, a herbivorous animal that ate massive amounts of food each day. Australotitan is the largest species of dinosaur ever found in Australia!

The paleontologists found that *A cooperensis* was closely related to three other Australian sauropods that lived during the Cretaceous period.

Quote: “We compared the three species found to the north, near Winton, to our new Eromanga giant and it looks like Australia’s largest dinosaurs were all part of one big happy family,” Dr. Hocknull said. “We found that *Australotitan cooperensis* was the largest in the family, followed by *Wintonotitan wattsi* with big hips and long legs, whilst the two smaller sauropods, *Diamantinasaurus matildae* and *Savannasaurus elliottorum* were shorter in stature and heavily-set.”

## Appearance in Jurassic Park and other media

### *Jurassic Park*

* Australotitan appeared in the game Jurassic World: Alive.

## References

1. ↑ http://www.sci-news.com/paleontology/australotitan-cooperensis-09741.html
2. ↑ https://www.washingtonpost.com/world/2021/06/08/australia-new-dinosaur-australotitan-cooperensis/
3. ↑ https://www.npr.org/2021/06/08/1003975808/australia-biggest-dinosaur-titanosaur-cooper-discovery-outback
4. ↑ https://www.bbc.com/news/world-australia-57394830
5. ↑ https://peerj.com/articles/11317/
6. ↑ https://www.npr.org/2021/06/08/1003975808/australia-biggest-dinosaur-titanosaur-cooper-discovery-outback
7. ↑ https://www.npr.org/2021/06/08/1003975808/australia-biggest-dinosaur-titanosaur-cooper-discovery-outback
8. ↑ http://www.sci-news.com/paleontology/australotitan-cooperensis-09741.html
9. ↑ https://www.scimex.org/newsfeed/meet-australias-largest-dinosaur-australotitan,-the-southern-titan
10. ↑ https://www.nytimes.com/2021/06/07/world/australia/new-dinosaur-species.html
11. ↑ https://www.eurekalert.org/pub\_releases/2021-06/p-mal060721.php
12. ↑ https://peerj.com/articles/11317/
13. ↑ https://www.npr.org/2021/06/08/1003975808/australia-biggest-dinosaur-titanosaur-cooper-discovery-outback