Leaellynasaura (Australia National Dinosaur Museum).


Leaellynasaura (Greek for "Leaellyn's lizard"); pronounced LAY-ah-ELL-ee-nah-SORE-ah


Plains of Australia

Historical Period:

Middle Cretaceous (105 million years ago)

Size and Weight:

About 10 feet long and 100 pounds



Distinguishing Characteristics:

Slim build; long tail; relatively large eyes and brain

About Leaellynasaura

If the name Leaellynasaura sounds a bit odd, that's because this is one of the few dinosaurs to be named after a living person: in this case, the daughter of Australian paleontologists Thomas Rich and Patricia Vickers-Rich, who discovered this ornithopod in 1989. The most striking thing about Leaellynasaura is how far south it lived: during the middle Cretaceous period, the continent of Australia was relatively cold, with long, dark winters. This would explain Leaellynasaura's relatively large eyes (which need to be that big in order to gather in all the available light), as well as its relatively small size, given the limited resources of its ecosystem. 

Since the discovery of Leaellynasaura, many other dinosaurs have been unearthed in the southern polar regions, including the vast continent of Antarctica. (See The 10 Most Important Dinosaurs of Australia and Antarctica.) This raises an important question: while the weight of opinion is that meat-eating dinosaurs had warm-blooded metabolisms, might this also have been the case for plant-eating ornithopods like Leaellynasaura, which needed a way to protect themselves from plunging temperatures? The evidence is inconclusive, even given the recent discovery of ornithopod dinosaurs bearing feathers (which are generally evolved by warm-blooded vertebrates as a means of insulation).