was a small ornithischian dinosaur that lived during the Early Cretaceous (around 106 million years ago). Leaellynasaura
is only known from a few fossils from Dinosaur Cove on Cape Otway, Victoria. She was discovered in 1987 in one of the three tunnels the research dig crews excavated with explosives to follow fossil-rich deposits into the sandstone cliffs. The genus was named after Leaellyn Rich, the daughter of the palaeontologists who described the species, and the species was named for the Friends of Museums Victoria ("amica
") and the National Geographic Society ("graphica
") who supported the Dinosaur Cove excavations.
would have stood on two legs, been around a metre and a half long and had a very long tail compared to its body, longer than any other ornithischian dinosaur. Like other ornithischians it was a herbivore and might have lived in small groups.
The global climate in the Cretaceous was warmer than today, and there was no ice at the poles. Even so, the environment in Victoria at the time would have been cool, as it lay within the Antarctic Circle. Australia had been connected to Antarctica but was separating, creating a massive rift valley filled with streams and forests in what would become Victoria. The bones of Leaellynasaura amicagraphica
were found in rocks formed from sediments deposited in the rivers of that rift valley.
The holotype (P 185991) of Leaellynasaura
is a piece of skull that fits with another part of that skull which preserves an endocast (an internal cast) showing what the top of the brain looked like. That skull fragment associated with the holotype shows that the eye sockets and the optic lobes of the brain were extremely large, suggesting Leaellynasaura
had the ability to "see in the dark". This would have been a great advantage for living in its polar environment where it was dark for prolonged periods.