The Thorny Devil is a unique looking species of Agamid lizard that is native to many parts of Australia.
This lizard is famous for the conical spikes that are all over its body. It was long believed that these spikes were a defensive trait but they also have other important functions.
This species of lizard has a number of other common names including the Mountain Devil, Thorny Dragon and simly just the Moloch.
Thorny Devil Taxonomy
In the Animal Kingdom, Taxonomy is used as the science and practice of classifying different species and sub-species based on their biological and genetic makeup.
Family
The Thorny Devil belongs to the Agamidae family of lizards. These lizards are commonly called Agamids and are often referred to as ‘Dragons’.
The Agamid family is a very large family of lizards with over 300 recognised species. They are native to Africa, Asia and Australia while a few species can also be found in Southern Europe.
Agamids are part of the infraorder Iguania which contains other popular families of lizards including Iguanas, Chameleons and Anoles.
The species in this family often have a somewhat similar appearance to iguanas and usually have strong powerful legs.
They also often share characteristics with chameleons such as the ability to slightly change color to regulate their body temperature.
Genus
The genus that the Thorny Devil belongs to is called Moloch and it is the only species in this genus.
This genus was created for the sole purpose of housing this lizard, which didn’t fit into any already created genera.
Species
The scientific name for the Thorny Devil is Moloch horridus and there are currently no recognised sub-species.
The species was first described in 1841 by a British zoologist named John Edward Gray.
While they have a somewhat similar appearance to the Horned Lizard of North America, the species aren’t closely related. Their similarities are believed to be an example of convergent evolution.
Thorny Devil Description
The Thorny Devil has numerous, large spines that cover its body. This is where the species gets its common name and it is what this lizard is best known for.
Their bodies are covered in a dense shield and spiky scales which makes this lizard look unique and a little intimidating.
They are brown and yellow in color which helps them plend into the background of their dry and arid natural habitat.
The scales of the lizard don’t overlap while the spikes are conical in shape. They have small eyes and a large spiny ‘boss’ on the back of their head.
All of these spikes that cover the body of the Thorny Devil were believed to serve as protection against predators.
However, it has since been learned that these spikes increase the surface area of the lizard, allowing them to absorb more water through body contact with moist surfaces.
The Thorny Devil has truly mastered living in arid environments. They have temperature-dependent skin tones which allows them to adjust how much heat their body absorbs.
If they want to absorb more heat, they can become browner or olive in color. However, if it is too hot, they will change to al lighter shade of yellow to avoid too much absorption.
They can also adjust their posture to minimize or increase the amount of contact they have with a hot surface.
Natural Habitat and Distribution
The Thorny Devil is endemic to Australia meaning this is the only place where the lizard is found naturally in the wild.
They have a very wide distribution and can be found throughout much of the Western half of Australia.
Their distribution extends through Western Australia and into the Northern Territory. They can also be found in South Australia and a small part of Western Queensland.
They can be found in a range of different habitats and temperature ranges with their distribution extending from the coastline right into the heart of the Outback.
They can be found throughout much of Western Australia with their range extending from coastal areas around Perth and Geraldton inland into the middle of the Outback.
There is also a large population of these lizards in the Central parts of Australia, extending from parts of the Northern Territory into Southern Australia.
They are only found on the Western outskirts of Queensland and we weren’t able to find any evidence of their presence in New South Wales or Victoria.
The Thorny Devil only lives in areas with sandy, desert soils. They are not found in rocky areas or places with hard soil.
Thorny Devil Behaviour
The Thorny Devil is a very adaptive species and can tolerate and remain active through a range of different temperatures.
The activity level of these lizards varies with the seasons. They tend to be most active during the fall which is around March to May.
They become most active again towards the end of winter, which in Australia is around August time. They remain active until December.
During the hottest months of the year which is around January and February, they become almost completely inactive.
Their activity level drops again during the coldest months, which is around June and July. During these periods of inactivity, they typically take refuge in burrows that they dig themselves
An interesting, yet kind of disgusting trait of the Thorny Devil is their use of a defecation site. These lizards have a preferred area where they will go to the toilet.
They will often walk to this same spot every time they need to go to the toilet and it is not uncommon for a build-up of faecal matter to build up in these spots.