The thorny devil (''Moloch horridus''), also known commonly as the mountain devil, thorny lizard, thorny dragon, and moloch, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of lizard in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Agamidae. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to Australia. It is the sole species in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Moloch''. It grows up to in total length (including tail), with females generally larger than males.

Taxonomy

The thorny devil was first described by the biologist

John Edward Gray John Edward Gray, FRS (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for ...

in 1841. While it is the only species contained in the genus ''Moloch'', many taxonomists suspect another species might remain to be found in the wild. The thorny devil is only distantly related to the morphologically similar North American

horned lizard Horned lizards (''Phrynosoma''), also known as horny toads or horntoads, are a genus of North American lizards and the type genus of the family Phrynosomatidae. The common names refer directly to their horns or to their flattened, rounded bodies, ...

s of the genus ''Phrynosoma''. This similarity is usually thought of as an example of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

. The names given to this lizard reflect its appearance: the two large horned scales on its head complete the illusion of a dragon or devil. The name

Moloch Moloch (; ''Mōleḵ'' or הַמֹּלֶךְ‎ ''hamMōleḵ''; grc, Μόλοχ, la, Moloch; also Molech or Molek) is a name or a term which appears in the Hebrew Bible several times, primarily in the book of Leviticus. The Bible strongly co ...

was used for a deity of the

ancient Near East The ancient Near East was the home of early civilizations within a region roughly corresponding to the modern Middle East: Mesopotamia (modern Iraq, southeast Turkey, southwest Iran and northeastern Syria), ancient Egypt, ancient Iran ( Elam, ...

, usually depicted as a hideous beast. The thorny devil also has other nicknames people have given it such as the "devil lizard", "horned lizard", and the "thorny toad".

Description

The thorny devil grows up to in total length (including tail), and can live for 15 to 20 years. The females are larger than the males. Most specimens are coloured in camouflaging shades of desert browns and tans. These colours change from pale colours during warm weather to darker colours during cold weather. The thorny devil is covered entirely with conical spines that are mostly uncalcified. Thorny devil pale

An intimidating array of spikes covers the entire upper side of the body of the thorny devil. These thorny scales also help to defend it from

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

Camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

and deception may also be used to evade predation. This lizard's unusual gait involves freezing and rocking as it moves about slowly in search of food, water, and mates. The thorny devil also features a spiny "false head" on the back of its neck, and the lizard presents this to potential predators by dipping its real head. The "false head" is made of soft tissue. The thorny devil's scales are ridged, enabling the animal to collect water by simply touching it with any part of the body, usually the limbs; the capillary principle allows the water to be transported to the mouth through the skin.

Distribution and habitat

The thorny devil usually lives in the arid scrubland and desert that covers most of central Australia, sandplain and sandridge desert in the deep interior and the mallee belt. The habitat of the thorny devil coincides more with the regions of sandy loam soils than with a particular climate in

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

Self-defense

The thorny devil is covered in hard, rather sharp spines that dissuade attacks by predators by making it difficult to swallow. It also has a false head on its back. When it feels threatened by other animals, it lowers its head between its front legs, and then presents its false head.

Predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

s that consume the thorny devil include wild birds and

goanna A goanna is any one of several species of lizards of the genus '' Varanus'' found in Australia and Southeast Asia. Around 70 species of ''Varanus'' are known, 25 of which are found in Australia. This varied group of carnivorous reptiles ranges ...

Diet

The thorny devil mainly subsists on ants, especially '' Ochetellus flavipes'' and other species in the '' Camponotus'', ''

Ectatomma ''Ectatomma'' is a Neotropical genus of ants in the subfamily Ectatomminae. The genus contains 17 described extant species and one extinct species. Distribution and habitat ''Ectatomma'' is one of the most common genera in the Neotropical regio ...

'', ''

Iridomyrmex ''Iridomyrmex'' is a genus of ants called rainbow ants (referring to their blue-green iridescent sheen) first described by Austrian entomologist Gustav Mayr in 1862. He placed the genus in the subfamily Dolichoderinae of the family Formici ...

'' (especially ''

Iridomyrmex rufoniger ''Iridomyrmex rufoniger'' is a species of ant in the genus ''Iridomyrmex''. It was described by Lowne in 1865. The species is endemic to Australia and introduced to several other countries. Taxonomy The species was first described by Lowne in 18 ...

''), ''

Monomorium ''Monomorium'' is a genus of ants in the subfamily Myrmicinae. As of 2013 it contains about 396 species. It is distributed around the world, with many species native to the Old World tropics. It is considered to be "one of the more important gr ...

'', ''

Ochetellus ''Ochetellus'' is a genus of ants first described by Steve Shattuck in 1992. He placed it in the subfamily Dolichoderinae of the family Formicidae. The ants in this genus are small and black in colour; workers measure in length, the males a ...

'', ''

Pheidole ''Pheidole'' is a genus of ants that belongs to the ant subfamily Myrmicinae. The genus is widespread and ecologically dominant. It probably includes more than 1000 species. The genus first evolved in the Americas, eventually spreading across t ...

'', or '' Polyrhachis'' genera. Thorny devils often eat thousands of ants in one day. The thorny devil collects moisture in the dry desert by the condensation of dew. This dew forms on its skin in the early morning as it begins to warm outside. Then the dew is channeled to its mouth in

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substan ...

grooves between its spines. During rainfalls,

capillary action Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces li ...

allows the thorny devil to absorb water from all over its body. Capillary action also allows the thorny devil to absorb water from damp sand. Absorption through sand is the thorny devil's main source of water intake.

Reproduction

The female thorny devil lays a clutch of three to ten eggs between September and December. She puts these in a nesting burrow about 30 cm underground. The eggs hatch after about three to four months.

Popular reference

The popular appeal of the thorny devil is the basis of an anecdotal petty scam. American servicemen stationed in Southwest Australia decades ago (such as during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

) were supposedly sold the thorny fruits of a species of weeds, the so-called "double gee" ('' Emex australis''), but those were called "thorny devil eggs" as a part of the scam. Thorny devils have been kept in captivity.

References

External links

Digimorph: ''Moloch horridus'', thorny dragon body structure
www.kidcyber.com.au {{Taxonbar, from=Q320665 Agamidae Reptiles of Western Australia Reptiles described in 1841 Agamid lizards of Australia Taxa named by John Edward Gray

Taxonomy

Description

Distribution and habitat

Self-defense

Diet

Reproduction

Popular reference

References

Further reading

External links