Rough nose horned lizard (Ceratophora aspera)
|Also known as:||rough horn lizard, Sri Lanka horned agama, Sri Lankan horned agama, Sri-lanka horned agama|
|Size||Total length: less than 9 cm (2)|
Snout-vent length: 2.8 - 3.8 cm (3)
- The rough nose horned lizard is named for the bizarre, rough-scaled appendage at the end of its snout.
- The ‘horn’ of the rough nose horned lizard is longer in males than in females, and is absent in juveniles.
- The exact function of the rough nose horned lizard’s ‘horn’ is unknown, but it may be used in competition between males.
- The rough nose horned lizard is found only in dense forests of south-western Sri Lanka.
The rough nose horned lizard is classified as Vulnerable (VU) on the IUCN Red List (1).
The rough nose horned lizard (Ceratophora aspera) is a small reptile which is named for the remarkable appendage at the end of its snout. This ‘horn’ is cylindrical in cross-section and covered in small, rough scales (3) (4) (5) (6), and it has been likened to a small pine cone in appearance (7). In the male rough nose horned lizard, the horn can be nearly as long as the animal’s head (4), but it is reduced in size in females (3) (6) (7) and is absent in juveniles (3). Despite being one of the smallest Ceratophora species (2) (6), the rough nose horned lizard has one of the most developed nasal appendages of this group (3).
The body of the rough nose horned lizard is slightly compressed and its limbs are quite long. The tail is rounded and of moderate length (4) (6). The rough nose horned lizard is well camouflaged against the leaf litter in the forests it inhabits (3), being largely dark brown to reddish, sometimes with lighter and darker markings (4) (6).
The male rough nose horned lizard tends to be slightly smaller and darker than the female (3) (6), and mature males may also have yellow on the lips and throat (6). Juvenile rough nose horned lizards are similar in colouration to the adults (6).
The rough nose horned lizard is found only in Sri Lanka, where it occurs in south-western parts of the island (1) (6).
A ground-dwelling species, the rough nose horned lizard inhabits dense, moist lowland and submontane forests at elevations of around 60 to 990 metres, in Sri Lanka’s ‘wet zone’ (1) (2) (6). It appears to be largely restricted to undisturbed patches of forest (1) (2), although it has also been reported in secondary forests (6).
Although usually found on the ground, often among leaf litter, moss-covered roots, boulders or logs (1) (8), the rough nose horned lizard has also been seen on small plants up to 20 centimetres above the ground (1).
Little information is available on the biology and behaviour of the rough nose horned lizard. However, like other Ceratophora species it is reported to be a slow-moving, sit-and-wait predator which lies in wait for prey and relies on its camouflage to escape predators. Like other members of the Agamidae family, the rough nose horned lizard is likely to be an egg-laying species (7).
The exact function of the rough nose horned lizard’s strange nasal appendage is not known, but it is possible that it is involved in interactions between rival males (3) (5). Other species in the genus have been known to be able to move their appendages slowly up and down while opening the mouth in a threat display (3) (6), and have also been reported to move it during contests between males (3).
Although the rough nose horned lizard is thought to be common in some areas, its forest habitat has been reduced and severely fragmented by ongoing deforestation (1) (2). Sri Lanka has lost almost all of its original wet zone forest due to land clearance for agriculture, as well as mining, logging, urbanisation and conversion to plantations (1). In addition, attempts at reforestation have usually consisted of monocultures of exotic tree species which do not support the island’s native wildlife (1) (2).
Little is known about this and other native lizard species in Sri Lanka, and many species are difficult to keep in captivity, which may hamper conservation efforts (2).
There are currently no conservation measures in place which specifically target the rough nose horned lizard. This species does occur in a number of protected areas, such as the Sinharaja National Heritage Wilderness Area, but illegal logging and encroachment often remain a problem (1).
Recommended conservation measures for this unusual lizard include minimising further habitat loss and adequately managing protected areas. Further research into the rough nose horned lizard’s populations, biology and habitat should also be carried out (1) (6) (8).
Although many related species are reported to be difficult to keep and breed in captivity (2), captive breeding of the rough nose horned lizard has been suggested as a safeguard against the loss of its wild populations due, for example, to fires or droughts (6). Captive breeding programmes for this and other species could also play a role in raising public awareness and aiding research into these poorly known reptiles (8).
Find out more about the rough nose horned lizard and other reptiles:
The Reptile Database:
More information on Sri Lankan reptiles:
Reptiles of Sri Lanka:
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- Genus: a category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.
- Secondary forest: forest that has re-grown after a major disturbance, such as fire or timber harvest, but has not yet reached the mature state of primary forest.
- Submontane forest: forest occurring in the foothills or lower slopes of a mountainous region.
IUCN Red List (August, 2013)
- Manamendra-Arachchi, K. and Liyanage, S. (1994) Conservation and distribution of the agamid lizards of Sri Lanka with illustrations of the extant species. Journal of South Asian Natural History, 1(1): 77-96.
- Johnston, G.R., Lee, M.S.Y. and Surasinghe, T.D. (2012) Morphology and allometry suggest multiple origins of rostral appendages in Sri Lankan agamid lizards. Journal of Zoology, 289(1): 1-9.
- Amarasinghe, A.A.T., Manthey, U., Stöckli, E., Ineich, I., Kullander, S.O., Tiedemann, F., McCarthy, C. and Gabadage, D.E. (2009) The original descriptions and figures of Sri Lankan agamid lizards (Squamata: Agamidae) of the 18th and 19th centuries. Taprobanica, 1(1): 2-15.
- Schulte II, J.A., Macey, J.R., Pethiyagoda, R. and Larson, A. (2002) Rostral horn evolution among agamid lizards of the genus Ceratophora endemic to Sri Lanka. Molecular Phylogenetics and Evolution, 22(1): 111-117.
- Pethiyagoda, R. and Manamendra-Arachchi, K. (1998) A revision of the endemic Sri Lankan agamid lizard genus Ceratophora Gray, 1835, with description of two new species. Journal of South Asian Natural History, 3(1): 1-50.
- Pianka, E.R. and Vitt, L.J. (2003) Lizards: Windows to the Evolution of Diversity. University of California Press, Berkeley.
De Silva, A., Molur, S. and Walker, S. (Eds.) (2000) Conservation Assessment and Management Plan: CAMP Report for Amphibians and Selected Taxa of Reptiles of Sri Lanka. CAMP Workshop, University of Peradeniya, Sri Lanka, 26-30 November 1998. Conservation Breeding Specialist Group, Sri Lanka. Available at: