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 appropriat ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia altho ...

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 Agamidae is a family (biology), family of over 300 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview phylogenetics, Phylogenetic ...

. 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 ...

Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

. 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 f ...

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 America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

n horned lizards 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 ...

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 t ...

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 Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It ...

and

desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...

that covers most of

central Australia Central Australia, also sometimes referred to as the Red Centre, is an inexactly defined region associated with the geographic centre of Australia. In its narrowest sense it describes a region that is limited to the town of Alice Springs and ...

, 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 Loam (in geology and soil science) is soil composed mostly of sand ( particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–si ...

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 t ...

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 t ...

s that consume the thorny devil include wild birds and goannas.

Diet

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

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''), ''

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 grou ...

'', ''

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'', 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 substance' ...

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 Southwest Australia is a biogeographic region in Western Australia. It includes the Mediterranean-climate area of southwestern Australia, which is home to a diverse and distinctive flora and fauna. The region is also known as the Southwest Aus ...

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 World War II by country, vast majority of the world's countries—including all of the great power ...

) 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