Log in Sign up
Back to Discover
🧬

Megalania

life science Maturity 5-7

A giant lizard lived in Australia.

Varanus priscus.png
Varanus priscus.png
It was very big. It had sharp teeth for eating. It lived a long time ago. We find its bones in the ground. Could you see it?
Extant Monitor lizards-Megalania SIZE.png
Extant Monitor lizards-Megalania SIZE.png

39 words

A giant lizard lived in Australia long ago.

Varanus priscus.png
Varanus priscus.png
It was the biggest land lizard ever. It had a large head and strong legs. Its teeth were sharp like blades.
Extant Monitor lizards-Megalania SIZE.png
Extant Monitor lizards-Megalania SIZE.png
This lizard ate large animals. It might have used venom to help it hunt. The venom helped its prey get sick. Scientists found its bones in the ground. It lived until about 50,000 years ago.
Varanus priscus skull.jpg
Varanus priscus skull.jpg
It is a very amazing creature.

79 words

Megalania was a giant lizard from Australia.

Varanus priscus.png
Varanus priscus.png
It is the largest land lizard ever found. Scientists study its bones to learn its size. Some think it was very long. Others think it was smaller.
Extant Monitor lizards-Megalania SIZE.png
Extant Monitor lizards-Megalania SIZE.png
It lived a long time ago. Its fossils date back to 50,000 years ago. This lizard was a top hunter. It had a big head and strong legs. Its teeth were sharp like blades. It likely ate large animals. It might have used venom to hunt. Venom is a toxin that can make prey sick. This toxin could stop blood from clotting.
Varanus priscus skull.jpg
Varanus priscus skull.jpg
This would make the prey bleed more. Megalania is related to the Komodo dragon. The Komodo dragon is a large lizard living today. Some people think early humans helped cause its extinction. They may have even met these lizards. The name Megalania means "ancient great roamer."

151 words

Megalania was a giant lizard that lived in Australia a long time ago.

Varanus priscus.png
Varanus priscus.png
It is known as the largest land lizard to ever exist. This animal was part of the megafauna, which are the huge animals that lived during the Pleistocene era. Because scientists only have broken pieces of bones, they are not sure about its exact size. Some studies suggest it could reach a very large total length. Other researchers have tried to find a more careful estimate. It likely played a big role in the ancient Australian environment.
Extant Monitor lizards-Megalania SIZE.png
Extant Monitor lizards-Megalania SIZE.png

This lizard was a powerful hunter with a very specific way of life. It had a large skull and a jaw full of teeth that looked like serrated blades. Its heavy body was supported by strong, built-up limbs. Scientists believe it may have used venom to help it hunt. This venom would come from glands inside its jaw. The venom was likely a haemotoxin, which is a substance that stops blood from clotting. This would cause prey to bleed more and go into shock. It probably ate medium to large animals, such as giant marsupials or large birds.

Varanus priscus skull.jpg
Varanus priscus skull.jpg

We first learned about this creature in 1859. A man named Sir Richard Owen described the first remains. He found three vertebrae, which are the bones that make up the spine. These bones were found near the Condamine River in eastern Australia. Owen gave it the name "Megalania prisca." This name means "ancient great roamer." He chose this name because the lizard spent its life roaming the land. Today, scientists call it Varanus priscus to show it is related to other monitor lizards.

Finding the exact size of Megalania is a hard job for scientists. In 2002, a researcher named Stephen Wroe suggested the lizard was smaller than people first thought. He estimated a maximum length of 5 meters. However, in 2009, Wroe and others raised that estimate back up. Some researchers like Erickson and his team looked at bone lengths in 2003. They thought one large individual could have been quite long. Other studies in 2012 compared bones to living lizards to find more clues. These different numbers show how much we are still learning from fossils.

Megalania.jpg
Megalania.jpg

You can think of Megalania as a much larger version of a Komodo dragon. The Komodo dragon is its closest living relative. Just like the Komodo dragon, Megalania was likely a top predator. Some fossils date back to about 50,000 years ago. This was around the time the first humans arrived in Australia. Some people think these early humans might have helped the lizards go extinct. The stories of these giant lizards might have even inspired old tales of scary creatures.

Extant Monitor lizards-Megalania SIZE.png
Extant Monitor lizards-Megalania SIZE.png

461 words

Megalania, scientifically known as Varanus priscus, was an extinct species of giant monitor lizard. It lived in Australia during the Pleistocene epoch. This creature was part of the megafauna, which refers to the large animals that inhabited the continent. Megalania is recognized as the largest terrestrial lizard to have ever existed.

Varanus priscus.png
Varanus priscus.png
However, determining its exact dimensions is difficult. Scientists only possess fragmentary remains rather than complete skeletons. Because of these incomplete fossils, size estimates remain highly uncertain among researchers.

Megalania.jpg
Megalania.jpg
The biology of Megalania suggests it was a powerful apex predator. It possessed a large skull with a small crest located between the eyes. Its jaw was filled with teeth that were serrated and shaped like blades. To support its massive weight, the lizard had heavily built limbs and a sturdy body. Its scales likely featured a honeycomb microstructure. This structure made the skin both durable and resistant to water evaporation.
Varanus priscus skull.jpg
Varanus priscus skull.jpg

Researchers believe Megalania may have used venom to hunt its prey. It belongs to a group called Toxicofera. This group includes reptiles that possess toxin-secreting oral glands. Many related varanid lizards use a potent haemotoxin found in glands inside the jaw. A haemotoxin acts as an anticoagulant, which means it stops blood from clotting. When a prey animal is bitten, the venom increases bleeding from the wounds. This causes a rapid decrease in blood pressure and leads to systemic shock. If this is true, Megalania may have been the largest venomous vertebrate known.

Extant Monitor lizards-Megalania SIZE.png
Extant Monitor lizards-Megalania SIZE.png
Estimating the size of Megalania has led to many different scientific conclusions. Early estimates placed the largest individuals at 6 meters long and 1,000 kilograms. In 2002, researcher Stephen Wroe suggested smaller sizes, such as a 5-meter length and 250 kilograms. However, in 2009, Wroe and others increased the estimate to at least 5 to 7 meters. In 2003, Erickson and colleagues suggested a large specimen could reach a snout-vent length of 3 meters. In 2012, Conrad and colleagues estimated that some individuals might reach over 5 meters in precaudal length. These variations occur because scientists must scale up from small bones like vertebrae.

ZOJ 448 f5.gif
ZOJ 448 f5.gif
The history of Megalania began in 1859. Sir Richard Owen described the first known remains of the species. He identified three vertebrae from a collection of bones purchased by the British Museum. These bones were collected from a tributary of the Condamine River in eastern Australia. Owen originally named the species "Megalania prisca." He used a modification of the Greek word "ēlainō," which means "I roam." This was meant to describe its terrestrial nature. Some people mistakenly translate the name as "ancient giant butcher" due to its similarity to the Latin word "lania."

Varanus priscus.png
Varanus priscus.png
Taxonomy is the science of naming and classifying organisms. While once considered its own genus, Megalania is now classified within the genus Varanus. This change was made because its morphology shows it is closely related to other Australian monitor lizards. Keeping it in the genus Varanus prevents that group from becoming an unnatural grouping. Ralph Molnar noted in 2004 that "megalania" is still a suitable term for common use, even if it is not the official scientific name. This places the animal in the same group as the Komodo dragon and the perentie.

Extant Monitor lizards-Megalania SIZE.png
Extant Monitor lizards-Megalania SIZE.png
The extinction of Megalania is linked to the Late Pleistocene. The youngest fossil remains date to approximately 50,000 years ago. This period coincides with the arrival of the first humans in Australia. Some scientists suggest that human predation or competition may have caused its disappearance. Studies of its limb musculature suggest Megalania was inefficient at outrunning early human settlers. While Megalania was a major predator, it shared the landscape with other hunters. These included the marsupial lion, Thylacoleo carnifex, and the terrestrial crocodile, Quinkana. The disappearance of Megalania remains a significant part of Australia's natural history.

648 words
🖼️ Images & Media (5)
File:Megalania.jpg
Megalania.jpg
File:ZOJ 448 f5.gif
ZOJ 448 f5.gif
File:Extant Monitor lizards-Megalania SIZE.png
Extant Monitor lizards-Megalania SIZE.png
File:Varanus priscus.png
Varanus priscus.png
File:Varanus priscus skull.jpg
Varanus priscus skull.jpg
Up Next
🧬
Monitor lizard
Life Science
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.