Leaellynasaura is a genus of ornithopod dinosaur from the Early Cretaceous Period. It was discovered in Dinosaur Cove, Australia. It was considered an Australian polar dinosaur as Australia was well within the Antarctic Circle during this time period. Leaellynasaura thrived further south than any reptile could today. With the discovery of other dinosaur genera discovered in Antarctica, it is suggested that dinosaurs could live in extreme climates and conditions, which were once thought to be unsuitable for any reptilian species.
It is thought that Leaellynasaura lived at least part of its life in the dark, as the sun would not rise for months at a time. This could be relevant to the extremely large eyes that this dinosaur had. Its brain also had large optic lobes, possibly evolving that way. Some scientists suggest that Leaellynasaura was warm-blooded.
Leaellynasaura was named after Leaellyn Rich, the daughter of paleontologists Tom and Patricia Rich who made the discovery. The type species is L. amicagraphica. This was a herbivorous dinosaur. This dinosaur made an appearance in the popular documentary series Walking with Dinosaurs.