| Psammophilus dorsalis | |
|---|---|
| Male in breeding colours (Hyderabad, India) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Iguania |
| Family: | Agamidae |
| Genus: | Psammophilus |
| Species: | P. dorsalis |
| Binomial name | |
| Psammophilus dorsalis (Gray, 1831)[1] |
|
Psammophilus dorsalis is a common species of agama found on rocky hills in south India. The informal names are Peninsular Rock Agama and South Indian Rock Agama. An allied species Psammophilus blanfordanus is found in the Eastern Ghats, but north of the range of this species.
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This species of Agamidae has a large head that is elongate and depressed with the cheeks swollen in adult males. The snout is longer than the diameter of the orbit (eye cavity). The upper head scales are unequal and smooth or obtusely keeled, the scales being larger on the sinciput (brow) than on the occiput. The canthus rostralis and supraciliary (brow) has a clear and sharp edge two small separated spines or groups of spines above the ear present or absent ; diameter of the tympanum half or a little more than half that of the orbit; 10 to 13 upper and as many lower labials. Body slightly flattened; dorsal scales small, uniform, smooth or feebly keeled in the adult, strongly in the young, all pointing backwards and upwards ; dorsal crest reduced to a ridge of enlarged scales; ventral scales as large as the dorsals, smooth (keeled in the young) ; from 115 to 150 scales round the middle of the body ; gular (under chin) scales are a little smaller than the ventral (scales on the underside) scales; 4 or 5 enlarged scales on the chin parallel with the anterior labials, separated from them by two rows of scales; a strong transverse fold covered with small scales is seen across the throat; nuchal and dorsal crests are merely tooth like protrusions. The legs are strong, covered with uniform keeled scales; the hind-limb when extended forward in a specimen reaches the ear or the rear end of the eye, and further forward in younger individuals. Tail is slightly flattened, covered with keeled scales which are larger below than above. In the adult male it is distinctly swollen at the base, the scales on that part of it thickened, those of the upper median row enlarged.
Young and females are olive-brown, spotted, speckled or marbled with dark brown, and with a series of white elongated spots along each side of the back. The male has pale brownish on the top of the head and back while the lips are yellowish-brown and this extends as a strip beyond the ear. A dark brown or black lateral stripe begins behind the eye and broadens to cover the lower sides. The underside is yellow with the throat mottled with grey.
These lizards basks on bare rocks where they are hidden by their cryptic colouration. They feed on insects. The male in the breeding season assumes bright colours. The upper parts become fine vermilion red or yellow, the lip-stripe sometimes pink. The under surfaces, limbs and tail are black.[2]
From snout to vent length is 135 millimetres, the tail is 200 mm. Females are smaller.
Males bask openly on exposed rocks and show head push up displays. The larger males take up higher perch positions.[3] They flatten their bodies when birds fly overhead.[4] Densities of about 90 lizards per hectare have been noted.[5]
Found in southern India, south of about 16 degrees latitude. In the Western Ghats, Nilgiris, South Arcot and Nallamalai Hills and found in the hilly regions at altitudes up to 6000 feet altitude in the Nilgiris. It is very common in some parts of the Nilgiris and it was noted as being particularly common near Bangalore by M. A. Smith in the Fauna of British India.[2]