Qantassaurus intrepidus (KWAHN-tuh-SORE-us) is a quick two-legged, plant-eating dinosaur that lived in Australia about 115 million years past, when the continent was still south of the Antarctic Circle. It was the size of a little grey kangaroo, and had huge eyes to help it see in the polar night. It was exposed by Patricia Vickers-Rich and her husband Tom Rich near Inverloch in 1996, and named after QANTAS, the Australian airline.
"The jaw is sole because it is short and stocky, whereas other jaws
in that dinosaur genus are long and slender"
— Patricia Vickers-Rich
Qantassaurus was about 1.8 meters (6 feet) long, and concerning 1 meter (3 feet) high. It had short thighs and long shins, so it was almost certainly a fast runner. Its four-toed feet had claws for traction, and the long tail almost certainly helped with turning. One characteristic of the hypsilophodontids and their more primitive ancestors is a spur, or trochanter, on the upper outside of the thigh bone (or femur), where muscle was attached.
It only had 12 teeth in its inferior jaw, while most hypsilophodontids had at least 14, so its face was probably short and stubby. It had a beak, with leaf-shaped teeth back in its cheek, which were hut as they wore down, and replaced by new teeth growing up from the jaw.
It lived 115 million years before in Australia, during the Albian age of the early Cretaceous time. At the time, Antarctica was part of the super continent of Gondwana, and within the Antarctic Circle. The standard temperature ranged from -6 to 3 °C (21 to 37 °F), and the polar night lasted up to 3 months.
They had several adaptations to survive in these conditions. Bone enlargement shows that hypsilophodontids were active all year round, so they did not hibernate from side to side the winter. The structure of hypsilophodontid bones also suggests that it may have been warm-blooded, which would help uphold its body heat. A surprising number of Australian hypsilophodontid fossils demonstrate signs of disease, which may show that they were washed away by the spring, melt after failing to survive the winter.
The brain of a related hypsilophodontid, Leaellynasaura, indicates it had large optic lobes, and large eyes, which may have helped it, see in the dark polar winter.
Qantassaurus was almost certainly a browser, who grabbed ferns and other vegetation with its five-fingered hands, and ran absent from predators like a modern gazelle. It may have had some kind of defensive camouflage, like spots.
Qantassaurus is a hypsilophodontid, at smallest amount in the loosest sense. Newer studies point to that the Hypsilophodontidae family is a paraphyletic group, so it will probably be broken up.
It is one of four named genus of hypsilophodontid from southeast Australia, along with Leaellynasaura amicagraphica, Atlascopcosaurus loadsi, and Fulgurotherium australe. The four species are typically known from isolated bones and teeth; however the thigh bones of F. australe are very varied and may belong to three separate genera.