Psammophilus dorsalis

Taxobox | name = Peninsular Rock Agama
status =


image_width = 240px
image_caption = Male in breeding colours (Hyderabad, India)
regnum = Animalia
phylum = Chordata
classis = Reptilia
ordo = Squamata
subordo = Iguania
familia = Agamidae
genus = "Psammophilus"
species = "P. dorsalis"
binomial = "Psammophilus dorsalis"
binomial_authority = (Gray, 1845) [Gray, J. E. 1831 A synopsis of the species of Class Reptilia. In: Griffith, E & E. Pidgeon: The animal kingdom arranged in conformity with its organisation by the Baron Cuvier with additional descriptions of all the species hither named, and of many before noticed [Vol. 9] . Whittaker, Treacher and Co., London: 481 + 110 pp.]
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The Peninsular Rock Agama "Psammophilus dorsalis" is a common species of agama found on rocky hills in south India.

Description

This Agama 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 feebly depressed; 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 scales are a little smaller than the ventrals ; 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 mere denticulation. Limbs strong, covered with uniform keeled scales; the hind-limb reaches to the ear or the posterior border of the orbit, sometimes a little farther in the young. Tail feebly compressed, 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 olive-brown, spotted, speckled or marbled with dark brown, and with a series of white elongated spots along each side of the back; this coloration more or less distinctly retained by the female. Male pale brownish on the top of the head and back ; lips yellowish-brown, the stripe extending to beyond the ear; a dark brown or black lateral stripe commencing from behind the eye and broadening to cover the whole of the lower half of the flank; yellowish below, the throat is usually variegated 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.Smith, M. A. 1941. Fauna of British India. Reptilia and Amphibia.]

From snout to vent 135 ; tail 200 mm. Females are smaller.

Distribution

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.

References