Earless Monitor Lizard: 15 Facts You Won’t Believe!

Earless monitor lizard facts shed light on this animal!

Want your child to enhance their knowledge about animals and learn about rare reptiles? Introduce him to this animal!

The Earless Monitor Lizards are the closest living descendants of the animal named Mosasaurs. The Mosasaurs became extinct in the late Cretaceous period. The genus Lanthanotus pertains to the fact that the reptile is earless, and 'borneensis' pays homage to its home, Borneo. These lizards are small and rare creatures. Human beings were unaware of their existence until they were discovered in the last century. These live a well camouflaged and reclusive life, active only in the dark of night because they are a nocturnal species! So reclusive are they that even the local community of the island to which the lizard is endemic had never known about the animal's existence or movement! Imagine an unknown animal creeping up your backyard! Surprising, huh?! Now it seems that they were better left alone because with discovery they have become prisoners of wildlife trafficking and a favorite amongst reptile collectors.

Like reading about this reptile? Want to know more? Read on!

If you like reading about this, you may also like reading about the marine iguana and the snapping turtle.

Earless Monitor Lizard

Fact File

What do they prey on?

Fish, Crustaceans, Earthworms

What do they eat?


Average litter size?

2-12 eggs

How much do they weigh?

1.7–4.2 oz (48-120 g)

How long are they?

16 in (40 cm)

How tall are they?


What do they look like?

Reddish-Brown, Scales, Forked Tongue, Small Limbs, Long Neck, Small Beaded Eyes, Long Claws

Skin Type

Dry Scales

What are their main threats?


What is their conservation status?


Where you'll find them

Rainforests, Streams, Palm Oil Plantations, Rice Fields


Southeast Asia (Borneo)





Scientific Name

Lanthanotus borneensis





Earless Monitor Lizard Interesting Facts

What type of animal is an earless monitor lizard?

The animals are members of phylum Chordata, order Squamata, superfamily Varanoidea, and species L.borneensis.

What class of animal does an earless monitor lizard belong to?

The animals are members of the class Reptilia, that is, they are reptiles.

How many earless monitor lizards are there in the world?

The earless monitor lizard has an endemic range and hence is not abundant in numbers.

Where does an earless monitor lizard live?

The animal is found in the northeastern area of the Southeast Asian island of Borneo. They are found in East Kalimantan, West Kalimantan, Sarawak, Malaysia, and Indonesia. Only in rare scenarios have they been witnessed outside of these places.

What is an earless monitor lizard's habitat?

The reptile's habitats range from rainforests, rocky streams, palm oil plantations, to rice fields. They prefer the tropical zone.

Who do earless monitor lizards live with?

The lizards may stay in groups, though they are also known to live alone.

How long does an earless monitor lizard live?

In captivity, the monitors have a lifespan of around seven and a half years.

How do they reproduce?

The Lanthanotus borneensis is oviparous. Their reproduction habits have been recorded only in captivity. The males and the females mate for long hours. Mating may last for almost two days at a time as has been seen amongst the animals in captivity. The female usually lays up to 12 eggs. Mating between the animals takes place in water and then the eggs are laid by the female on land.

What is their conservation status?

The monitors have not yet been assessed by the International Union for  Conservation of Nature (IUCN) Red List of Threatened Species. They are proposed to be listed under Convention on International Trade in Endangered Species (CITES) Appendices. Also, they are under protection separately in most of the nations where they are found now. By name, the nations are Malaysia, Brunei, and Indonesia.

Earless Monitor Lizard Fun Facts

What do earless monitor lizards look like?

The reptile is a native to the island of Indonesian Borneo!

The lizards, Lanthanotus borneensis have a scaly appearance and a cylindrical body shape. They are small in length. They are dark to reddish-brown in color. They have long necks and short limbs. They have long sharp claws and small beaded eyes. There are no visible ear openings. They have no tympanum, which is a common ear appendage in reptiles. Sexual dimorphism is visible from around three years of age. The animal has a prehensile tail. If the tail is hurt or damaged in some way, it cannot be regenerated. They have a forked tongue.

How cute are they?

We don't think they are particularly cute!

How do they communicate?

They make a gentle and squeaky sound.

How big is an earless monitor lizard?

The males are broader than the females. The earless monitor lizards are 16 in (40 cm) in length. They are smaller than the other monitor lizards.

How fast can an earless monitor lizard run?

The lizards are usually inactive. However, they can run pretty fast if the need to arises.

How much does an earless monitor lizard weigh?

The weight of the lizard is around 1.7–4.2 oz (48 to 120 g).

What are the male and female names of the species?

The males and females of the earless monitor lizard do not have different names.

What would you call a baby earless monitor lizard?

A baby monitor is called a hatchling! They reach sexual maturity at two years of age.

What do they eat?

The monitors are carnivorous animals. They feed on fish, crustaceans, and earthworms in the wild.  In captivity, they may be fed yolks from the eggs of turtles, baby mice, chicken, and pig liver.

Are they poisonous?

Scientists have traced venom in the bites of the earless monitor lizard, Lanthanotus borneensis. However, the venom of this species is less potent as compared to the venom of other lizards.

Would they make a good pet?

This species may make good pets, however, possessing them is illegal in most nations. Even captive breeding is illegal in many places.

Did you know...

Even today these remain one of the lesser-studied species in the wild and about whom humans are more curious! They are extremely shy and elusive.

This species has become quite popular in the online reptile pet trade, wildlife trade, and wildlife trafficking. To the reptile collectors, this beautiful species has become the 'Holy Grail'. The online trade was tracked by TRAFFIC and mentioned by Sarah Stoner. TRAFFIC is a wildlife trade monitoring network with headquarters in the United Kingdom.

Moscow zoo became home to some temporary residents in 2016 when they were caught being illegally smuggled from Hong Kong. A ban on the commercial trading of the reptile at the international level is now in place.

These lizards have excellent movement in the water and are great swimmers!  Though their limbs are not long, they still make great use of their limbs and neck. Also, they can hold their breath for a long time underwater.

During the day they are found in burrows dug deep under ground.

The adult males are aggressive in defending their territories. Often they involve in fights with other males that leave one or both of them injured in the head or neck or ear.

The animals have semitransparent lower eyelids which remain closed underwater. In the wild, when they are underwater they hold onto rocks or stones or some other materials so they are not swept away by floods.

These animals can swallow their prey even when they are submerged underwater. The snout to vent length in the adults is around 20 cm.

It is essentially a lowland species that is found at around 300 m above sea level and prefers rocky water bodies. It was described for the first time in 1878 by  Franz Steindachner. It was Steindachner who gave the scientific synonyms to the animal. It is the only member of the Lanthanotidae family.

Lizards can recognize their owners. Monitor lizards do not tend to attack humans unless they are disturbed. They may bite, however, their bite is not fatal and may heal if tended properly. Komodo dragons, though, can injure or even kill human beings!

These animals have a number of names in local languages. They are called Biawak Kalimantan in Indonesia, Kukang in Brunei, and Cicak purba in Sarawak. What interesting names the animal has!

Can earless monitor lizards hear?

Though the name suggests that these are earless yet the monitor lizard, Lanthanotus borneensis, of the superfamily Varanoidea, can hear. However, there are no visible external ear appendages. The low-frequency sounds on the ground are more important than the sounds borne in the air.

Do monitor lizards show affection?

The animals tend to prefer some people more than others. Also, they like it when they are stroked.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other reptiles including tortoise facts or black caiman facts.

You can even occupy yourself at home by coloring in one of our free printable earless monitor lizard coloring pages.



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