Thorny devil

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Thorny devil
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Agamidae
Subfamily: Amphibolurinae
Genus: Moloch
Gray, 1841
M. horridus
Binomial name
Moloch horridus
Gray, 1841
Moloch horridus distribution map.png
Distribution of Moloch horridus

Acanthosaura gibbosus

The thorny devil (Moloch horridus), also known commonly as the mountain devil, thorny lizard, thorny dragon, and moloch, is a species of lizard in the family Agamidae. The species is endemic to Australia. It is the sole species in the genus Moloch. It grows up to 21 cm (8.3 in) in total length (including tail), with females generally larger than males.



The thorny devil was first described by the biologist John Edward Gray 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. [2] The thorny devil is only distantly related to the morphologically similar North American horned lizards of the genus Phrynosoma. This similarity is usually thought of as an example of convergent evolution.

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 was used for a deity of the ancient Near East, usually depicted as a hideous beast. [3] The thorny devil also has other nicknames people have given it such as the "devil lizard", "horned lizard", and the "thorny toad". [4]


The thorny devil grows up to 21 cm (8.3 in) in total length (including tail), [5] 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.

A thorny devil in Western Australia Thorny devil pale.jpg
A thorny devil in Western Australia

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 predators. Camouflage 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. [2]

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. [6]

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. [2]

Distribution and habitat

Illustration from Lydekker's The Royal Natural History MolochLyd.jpg
Illustration from Lydekker's The Royal Natural History
Thorny devil underside, Western Australia Thorny Devil crop.jpg
Thorny devil underside, Western Australia

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. [7]


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


The thorny devil mainly subsists on ants, especially Ochetellus flavipes and other species in the Camponotus , Ectatomma , [8] Iridomyrmex (especially Iridomyrmex rufoniger ), [9] Monomorium , [10] Ochetellus , Pheidole , or Polyrhachis [11] genera. [12] Thorny devils often eat thousands of ants in one day. [2]

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 grooves between its spines. [13] During rainfalls, capillary action 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. [14]


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. [15]

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) 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.[ citation needed ] Thorny devils have been kept in captivity. [2]

Related Research Articles

<span class="mw-page-title-main">Lizard</span> Informal group of reptiles

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 although some lizards are more closely related to these two excluded groups than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3-meter-long Komodo dragon.

<span class="mw-page-title-main">Agamidae</span> Family of lizards

Agamidae is a 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.

<span class="mw-page-title-main">Horned lizard</span> Genus of reptiles

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, and blunt snouts.

<span class="mw-page-title-main">Greater short-horned lizard</span> Species of reptile

The greater short-horned lizard, also commonly known as the mountain short-horned lizard, is a species of lizard endemic to western North America. Like other horned lizards, it is often called a "horned toad" or "horny toad", but it is not a toad at all. It is a reptile, not an amphibian. It is one of seven native species of lizards in Canada.

<span class="mw-page-title-main">Frilled lizard</span> Species of reptile

The frilled lizard or frill-necked lizard is a species of lizard in the family Agamidae. It is native to northern Australia and southern New Guinea. This species is the only member of the genus Chlamydosaurus. Its common names come from the large frill around its neck, which usually stays folded against the lizard's body. It reaches 90 cm (35 in) from head to tail and can weighs 600 g (1.3 lb). Males are larger and more robust than females.

<span class="mw-page-title-main">Texas horned lizard</span> Species of lizard

The Texas horned lizard is one of about 14 North American species of spikey-bodied reptiles called horned lizards, all belonging the genus Phrynosoma. It occurs in south-central regions of the US and northeastern Mexico, as well as several isolated introduced records and populations from Southern United States. Though some populations are stable, severe population declines have occurred in many areas of Texas and Oklahoma. The Texas spiny lizard may be confused for a Texas horned lizard due to its appearance and overlapping habitat.

<span class="mw-page-title-main">Desert horned lizard</span> Species of lizard

The desert horned lizard is a species of phrynosomatid lizard native to western North America. They are often referred to as "horny toads", although they are not toads, but lizards.

Moloch is the name of a god associated with child sacrifice in the Hebrew Bible and with Phoenician religion.

<span class="mw-page-title-main">Namaqua chameleon</span> Species of lizard

The Namaqua chameleon is a ground-living lizard found in the western desert regions of Namibia, South Africa and southern Angola.

<i>Iridomyrmex</i> Genus of ants

Iridomyrmex is a genus of ants called rainbow ants first described by Austrian entomologist Gustav Mayr in 1862. He placed the genus in the subfamily Dolichoderinae of the family Formicidae. It has 79 described species and five fossil species. Most of these ants are native to Australia; others are found in Asia and Oceania, and they have been introduced to Brazil, New Zealand, and the United Arab Emirates. Fossil species are known from China, France, and the United States.

<span class="mw-page-title-main">Meat ant</span> Species of ant

The meat ant, also known as the gravel ant or southern meat ant, is a species of ant endemic to Australia. A member of the genus Iridomyrmex in the subfamily Dolichoderinae, it was described by British entomologist Frederick Smith in 1858. The meat ant is associated with many common names due to its appearance, nest-building behaviour and abundance, of which its specific name, purpureus, refers to its coloured appearance. It is among the best-known species of ant found throughout Australia; it occurs in almost all states and territories except for Tasmania. Its enormous distribution, aggression and ecological importance have made this ant a dominant species.

<span class="mw-page-title-main">Amphibolurinae</span> Subfamily of lizards

The Amphibolurinae are a subfamily of lizards in the family Agamidae. Members of this subfamily are found in Australia and New Guinea, although one species, the Chinese water dragon, is found in Southeast Asia.

<i>Ochetellus glaber</i> Species of ant

Ochetellus glaber is a species of ant native to Australia. A member of the genus Ochetellus in the subfamily Dolichoderinae, it was described by Austrian entomologist Gustav Mayr in 1862. Aside from Australia, O. glaber has been introduced to a number of countries, including China, India, Japan, New Zealand, the Philippines and the United States, where it has established itself in Hawaii and Florida. It has been found on Lord Howe Island, New Caledonia, Norfolk Island, Réunion and the Solomon Islands. Compared with other ants, O. glaber is a small species, with workers measuring 2–3 mm (0.079–0.118 in). Males are the smallest at 1.6 mm (0.063 in), while the queens measure 5.2–5.5 mm (0.20–0.22 in). The ant's colour ranges from brown to black.

M. horridus may refer to:

<span class="mw-page-title-main">Mexican horned lizard</span> Species of lizard

The Mexican horned lizard is a horned lizard species native to Mexico. Horned lizards are sometimes referred to as "horned toads" or "horny toads", although they are not toads. Compared to other members of the horned lizards, little is known about this species.

<span class="mw-page-title-main">Regal horned lizard</span> Species of lizard

The regal horned lizard is a horned lizard species native to Mexico and the Southwest United States.

<i>Ochetellus</i> Genus of ants

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 1.75 to 3 millimetres in length, the males at around 1.6 millimetres (0.06 in) are smaller, and the queens are the largest, reaching 4 millimetres (0.16 in). There are seven described species and three described subspecies that mostly live in Australia in a wide variety of habitats, but some species are found in Asia. One species, Ochetellus glaber, has been introduced into New Zealand and the United States.

<i>Ctenophorus caudicinctus</i> Species of lizard

Ctenophorus caudicinctus, commonly known as the ring-tailed dragon or ring-tailed bicycle-dragon is a native species of agamid lizard occurring in rocky ranges and outcrops of Australia. Ctenophorus caudicinctus is most commonly found in the Pilbara region and offshore islands of Western Australia. The ctenophorus has 28 known species in the northern, southern, and western parts of Australia. It is recognized to be the most speciose group of Australian agamids.

Ctenophorus mckenziei, more commonly known as the dwarf-bicycle dragon, is a species of endemic Australian lizard within the family Agamidae and genus Ctenophorus. Originally identified as the agamid Amphibolurus mckenziei, the lizard had been identified within the regions of Western Australia and South Australia in which it occupied the shrubbery and woodland areas as its habitat. It was subsequently transferred to the genus Ctenophorus along with other Agamid species in which it shared similar morphology and characteristics. The name mckenziei is in reference to Norman Leslie Mckenzie, who was a zoologist and discovered the existence of the lizard. Listed on the IUCN red list page, threats to its population numbers are evaluated as least concern; however, their numbers are threatened by habitat loss, climate change, and feral predators.

The Southern Mallee ctenotus is a medium sized lizard in the family scincidae (skink) found in the central and southern interior regions of South Australia and Western Australia; the Mallee regions of NSW and Victoria, in Australia.


  1. Doughty, P.; Melville, J.; Craig, M.; Sanderson, C. (2017). "Moloch horridus". IUCN Red List of Threatened Species . 2017: e.T83492011A83492039. doi: 10.2305/IUCN.UK.2017-3.RLTS.T83492011A83492039.en . Retrieved 19 November 2021.
  2. 1 2 3 4 5 Browne-Cooper, Robert; Bush, Brian; Maryan, Brad; Robinson, David (2007). Reptiles and Frogs in the Bush: Southwestern Australia. University of Western Australia Press. pp. 46, 65, 158. ISBN   978-1-920694-74-6.
  3. Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). "Moloch horridus" in The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. p. 182. ISBN   978-1-4214-0135-5.
  4. Thorny Devil Lizard – Prickly Desert Ant-Eater.
  5. Boulenger GA (1885). "Moloch horridus" in Catalogue of the Lizards in the British Museum (Natural History). 2nd Ed. Vol. I. ... Agamidæ.. Taylor and Francis. pp. 411–412.
  6. Bell, Christopher; Mead, Jim; Swift, Sandra (2009). "Cranial osteology of Moloch horridus (Reptilia: Squamata: Agamidae)". Records of the Western Australian Museum. 25 (Part 2): 201–237. doi: 10.18195/issn.0312-3162.25(2).2009.201-237 .
  7. Pianka ER, Pianka HD (1970). "The ecology of Moloch horridus (Lacertilia: Agamidae) in Western Australia". Copeia. 1970 (1): 90–103. doi:10.2307/1441978. JSTOR   1441978.
  8. "Moloch horridus (Thorny Devil, Mountain Devil)".
  9. "Moloch horridus (Thorny Devil, Mountain Devil)".
  10. "Moloch horridus (Thorny Devil, Mountain Devil)".
  11. "Moloch horridus (Thorny Devil, Mountain Devil)".
  12. Australia's Thorny Devil , retrieved 31 October 2007
  13. Bentley PJ, Blumer FC (1962). "Uptake of water by the lizard, Moloch horridus". Nature. 194 (4829): 699–700. Bibcode:1962Natur.194..699B. doi:10.1038/194699a0. PMID   13867381. S2CID   4289732.
  14. Knight, Kathryn (2016). "How thorny devils tap damp sand to slake thirst". The Journal of Experimental Biology. 219 (21): 3309.1–3309. doi: 10.1242/jeb.151407 . S2CID   89521720.
  15. Pianka ER (1997). "Australia's thorny devil". Reptiles. 5 (11): 14–23.

Further reading