Thorny Devil
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Secure
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| Moloch horridus Gray, 1841 |
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The Thorny Devil (Moloch horridus) is an Australian lizard. It is also known as the Thorny Dragon, Thorny Lizard, or the Moloch and is the sole species of genus Moloch.
It grows up to 20 cm (8 in) in length, 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 helps the animal collect water which is channelled to the mouth.[1]
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[edit] Description
An intimidating array of spines cover the entire upper side of the body, these thorny scales are a defence 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]
 Thorny devil |
 Thorny devil, Western Australia |
 The devil is gentle when handled |
[edit] 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.
[edit] Habitat
It inhabits arid scrub and desert over most of central Australia. In particular, it inhabits spinifex-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 (Pianka and Pianka 1970).
[edit] Diet
The food that the devil mainly eats is ants, often Iridomyrmex or Ochetellus (early reports[2] indicate Iridomyrmex flavipes as the predominant prey, but this species was renamed Ochetellus flavipes in 1992[3]). They can eat some 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 (Bentley and Blumer 1962), and also during rain events. Capillary action allows the lizard to suck in water from its belly, all over the body, with capillaries ending near its mouth.
[edit] 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 (Pianka 1997).
Predators include buzzards and goannas.
[edit] Popular reference
The popular appeal of the thorny devil is the basis of an anecdotal petty scam; American serviceman 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]
[edit] 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 9778 1 920694 74 6.
- ^ Australia's Thorny Devil. Retrieved on 2007-10-31.
- ^ Australian Ants Online: Genus Ochetellus. Retrieved on 2007-10-31.]
- Bentley, P. J. and F. C. Blumer. 1962. Uptake of water by the lizard, Moloch horridus. Nature 194: 699-700.
- Pianka, E. R. 1997. Australia's thorny devil. Reptiles 5(11): 14-23.
- Pianka, E. R. and H. D. Pianka. 1970. The ecology of Moloch horridus (Lacertilia: Agamidae) in Western Australia. Copeia 1970: 90-103.
- Science Podcast on belly-water-suction mechanism, August 24, 2007
[edit] External links
