Leaellynasaura amicagraphica
Leaellynasaura was a small, two-legged plant-eating ornithopod from southern Australia. Its body was barely bigger than a turkey's, but its tail was extraordinary: a partly articulated specimen from Victoria suggests more than 70 tail vertebrae, giving it proportionally the longest tail of any small ornithopod known.
Leaellynasaura
Leaellynasaura amicagraphica
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Quick facts
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Weight
4–10 kg
Length
0.9–2 m
Diet
Herbivore
Period
Cretaceous
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4–10 kg
0.9–2 m
Cretaceous
Bipedal
30–60 cm
Herbivore
4 recorded fossil finds in Australia. First described in 1989 by Rich and Vickers-Rich.
Sites and counts from the Paleobiology Database
The timeline shows the whole age of dinosaurs – and how much time has passed since. The glowing part is when Leaellynasaura lived.
million years ago
Lived 113–106 million years ago
If the whole age of dinosaurs were a single day, Leaellynasaura lived at 18:23.
Chapter • Meet the dinosaur
Leaellynasaura was a small, two-legged plant-eating ornithopod from southern Australia. Its body was barely bigger than a turkey's, but its tail was extraordinary: a partly articulated specimen from Victoria suggests more than 70 tail vertebrae, giving it proportionally the longest tail of any small ornithopod known. Including that tail, estimates run from about 0.9 m for the juvenile holotype up to perhaps two metres for a full-grown adult, at a weight of only a few kilograms. The hind limbs were long and slender, the forequarters small and the neck lightly built.
Chapter • Where it lived
Leaellynasaura lived roughly 113–106 million years ago, in the Early Cretaceous (Albian), in what is now Victoria, southeastern Australia. The fossils come from the Eumeralla Formation, above all from Dinosaur Cove west of Cape Otway. Australia and Antarctica were still joined, and the area lay in a long rift valley of broad floodplains, braided rivers and forests of conifers, ginkgos, ferns and early flowering plants. The climate was cool and wet by Cretaceous standards — published mean annual temperature estimates range from slightly below freezing to about +8 °C — with a polar winter that brought little or no daylight.
Chapter • Wild behavior
Cathemeral
Small ornithopod bones are common in the Eumeralla Formation and several individuals have turned up in the same beds, which has led some researchers to suggest these animals moved in groups. There is no firm evidence, however — no single-species bonebed and no multi-individual trackways — so herding in Leaellynasaura stays a plausible but unconfirmed hypothesis.
The name means roughly 'Leaellyn's lizard', honouring Leaellyn Rich, daughter of palaeontologists Tom Rich and Patricia Vickers-Rich, who described the animal in 1989.
The species name amicagraphica honours the 'writing friends': the Friends of the Museum of Victoria and the National Geographic Society, who funded the digs.
The fossils come from Dinosaur Cove, a coastal site in Victoria where crews blasted and drilled tunnels into the cliff to follow the fossil-bearing layer.
In the Cretaceous the site lay at roughly 70 degrees south, well inside the polar circle of the time, with weeks or months of winter darkness.
One specimen indicates over 70 tail vertebrae — a tail far longer than the rest of the animal.
The large eye sockets and apparently enlarged optic lobes have been read as a low-light adaptation, but the holotype is a juvenile and young animals naturally have big eyes, so the idea remains debated.
Bone histology of Victoria's polar dinosaurs shows growth that continued year-round, arguing against hibernation through the polar winter.
Leaellynasaura is one of very few dinosaurs named after a child.
Chapter • Scientific place
National Geographic Research / Monash University Research Portal
Reviewed: 9/8/2026
Rich & Rich (1989), the original description that named Leaellynasaura amicagraphica and established its ornithischian/ornithopod classification.
Open sourceAustralian Museum
Reviewed: 9/8/2026
Documents the holotype and referred specimens and their fossil localities in the Early Cretaceous of Dinosaur Cove, Victoria, southeastern Australia.
Open sourceAlcheringa: An Australasian Journal of Palaeontology
Reviewed: 9/8/2026
Peer-reviewed documentation of the high-latitude floodplain palaeoenvironment of the Eumeralla Formation in which Leaellynasaura lived.
Open sourceNatural History Museum, London
Reviewed: 9/8/2026
Museum taxon page identifying Leaellynasaura as a plant-eating (herbivorous) ornithopod dinosaur.
Open sourcePalaeontology (The Palaeontological Association)
Reviewed: 9/8/2026
Extinct taxon; conservation status NE
Open sourceNatural History Museum, London
Reviewed: 9/8/2026
General authoritative overview of Leaellynasaura covering its size, diet, age and geographic occurrence.
Open sourceNatural History Museum, London
Reviewed: 9/8/2026
General authoritative overview of Leaellynasaura covering its size, diet, age and geographic occurrence.
Open sourceNatural History Museum, London
Reviewed: 9/8/2026
General authoritative overview of Leaellynasaura covering its size, diet, age and geographic occurrence.
Open sourceNatural History Museum, London
Reviewed: 9/8/2026
General authoritative overview of Leaellynasaura covering its size, diet, age and geographic occurrence.
Open source