- Thorny Devil
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Thorny Devil 
Scientific classification Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Squamata Suborder: Lacertilia Family: Agamidae Subfamily: Agaminae Genus: Moloch Species: M. horridus Binomial name Moloch horridus
Gray, 1841
Synonyms Acanthosaura gibbosus
Thorny Devil (Moloch horridus) is an Australian lizard. It is also known as the Thorny Dragon, Mountain Devil, Thorny Lizard, or the Moloch and is the sole species of genus Moloch. It grows up to 20 cm (8 in) in length and can live up to 20 years, coloured in camouflaging shades of desert browns and tans; these change from pale colours when warm to darker colours when cold. The species is entirely covered with conical spines that are mostly uncalcified. It also features a spiny "false-head" on the back of the neck, the animal presents this to a potential predator by dipping its real head. Females are larger than males. The Thorny Devil's body is ridged in structure, and enables the animal to collect water from any part of its body, which is then channelled to the mouth.[1]
Contents
Description
Thorny Devil, Western Australia
An intimidating array of spikes cover the entire upper side of the body; these thorny scales are a defense mechanism against predators. Camouflage and deception may also be used to evade predation. It has an unusual gait, involving freezing and rocking, as it slowly moves in search of its preferred diet.[1]
Taxonomy and naming
The names of this dragon are given for its appearance, two large horned scales on the head complete the allusion to a devil. The species was described by John Edward Gray in 1841. While the species is the only one contained by the genus Moloch, taxonomists believe that another species may yet be described.[1] The thorny devil is only distantly related to the morphologically similar North American horned lizards of the genus Phrynosoma, and is more an example of convergent evolution.
Habitat
Illustration from Lydekker's The Royal Natural History
Thorny devil underside, Western AustraliaIt inhabits arid scrub and desert over most of central Australia. In particular, it inhabits spinifex (triodia) sandplain and sandridge desert within the interior and mallee belt. Its distribution largely coincides more with the distribution of sandy and sandy loam soils than with a particular climate in western Australia.[2]
Defenses
The thorny devil is covered in hard, somewhat sharp spines to dissuade predators by making it difficult to swallow. It also has a false head on its back: when it feels threatened it lowers its head between its front legs, and only the false head is visible.
Diet
The food that the devil mainly eats is ants, often Iridomyrmex or Ochetellus (early reports[3] indicate Iridomyrmex flavipes as the predominant prey, but this species was renamed Ochetellus flavipes in 1992[4]). They can eat thousands of ants in one day.[1] They collect moisture in the dry desert via night-time condensation of dew which forms on the skin and is channelled to the mouth in hygroscopic grooves between its spines.[5] During rain events, capillary action allows the lizard to suck in water from all over its body.
Ecology
A clutch of three to ten eggs is laid in September-December (spring-summer) in a nesting burrow about 30 cm underground, and hatches after an incubation of three to four months.[6]
Predators include buzzards and goannas.
Popular reference
The popular appeal of the thorny devil is the basis of an anecdotal petty scam; American servicemen stationed in Southwest Australia were reputed to have been sold the thorny fruits of a weed species, called Double Gees (Emex australis), as 'thorny devil eggs'. The species has been kept in captivity, and is able to be handled.[1]
References
- ^ a b c d e Browne-Cooper, Robert; Brian Bush, Brad Maryan, David Robinson (2007). Reptiles and Frogs in the Bush: Southwestern Australia. University of Western Australia Press. pp. 46, 65, 158. ISBN 978 1 920694 74 6.
- ^ Pianka, E. R. and H. D. Pianka. 1970. The ecology of Moloch horridus (Lacertilia: Agamidae) in Western Australia. Copeia 1970: 90-103.
- ^ "Australia's Thorny Devil". http://uts.cc.utexas.edu/~varanus/moloch.html. Retrieved 2007-10-31.
- ^ "Australian Ants Online: Genus Ochetellus". Archived from the original on 2007-08-30. http://web.archive.org/web/20070830131921/http://www.ento.csiro.au/science/ants/dolichoderinae/ochetellus/ochetellus_tax_cat.htm. Retrieved 2007-10-31.]
- ^ Bentley, P. J. and F. C. Blumer. 1962. Uptake of water by the lizard, Moloch horridus. Nature 194: 699–700. doi:10.1038/194699a0
- ^ Pianka, E. R. 1997. Australia's thorny devil. Reptiles 5(11): 14-23.
- Science Podcast on belly-water-suction mechanism, 24 August 2007
- Moloch horridus, The Reptile Database
External links
Categories:- Agamidae
- Reptiles of Australia
- Reptiles of Western Australia
- Monotypic reptile genera
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