The Fan-throated lizard (Sitana ponticeriana) is a species of agamid lizard

Lizard

Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...

 found in Nepal

Nepal

Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...

, India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, Sri Lanka

Sri Lanka

Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...

, and parts of Pakistan

Pakistan

Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

.

The species is found mostly on the ground in open ground patches in thin forest

Forest

A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

. When disturbed this lizard sometimes runs with a bipedal gait.

Descriptions

Upper head-scales small, sharply keeled; canthus rostralis and supraciliary edge sharp, with much enlarged scales. Dorsal scales larger than ventrals, with sharp keels forming straight longitudinal lines; lateral scales smallest, uniform or intermixed with scattered enlarged ones. The fore limb does not extend on to the vent, if laid backwards; the hind limb reaches to the orbit, if laid forwards; the lower thigh is rather shorter than the foot (measured from the heel to the tip of the longest toe), the length of which is only three-fourths of the distance between the shoulder and hip joints. Limbs above with uniform strongly keeled scales. The length of the limbs varies very much : in some specimens the hind limb stretched forwards does not extend beyond the orbit, in others it reaches the end of the snout or even considerably beyond. Brown, with a series of dark spots along the middle of the back, the spot on the neck being the darkest; a whitish band along each side of the back. Gular appendage tricoloured—blue, black, and red.

Tail round, slender, once and a half to twice as long as the head and body, covered with equal keeled scales. Olive-brown above, with a series of rhomboidal spots along the middle of the back; a more or less distinct light band along each side of the back. Gular appendage tricoloured—blue, black, and red; this appendage is more developed in the breeding-season, and in the majority of individuals, at all events, is not coloured at other times.

This species attains a maximum length of 8 inches, of which the tail takes 5 inches. From snout to vent 3-5 inches.
Ebanasar (1989) reported the histomorphology of thyroid gland and thyroid activity in Sitana ponticeriana in juveniles, males and females with different ovary maturation stages. He has also reported ovoviviparity in females from Madurai and virudhunagar areas of Tamil Nadu.

M. A. Smith notes that there are two size variants with intermediates :

• A larger form. From snout to vent 70–80 mm. ; tail once and a half to twice the length of the head and body ; hind-limb not reaching to beyond the snout;, lateral scales not intermixed with larger ones ; no enlarged scales on the occiput. This form appears to be confined to the district around Bombay. This may possibly represent Jerdon's deccanensis.
• A smaller form. From snout to vent 40–50 mm. ; tail two to three times the length of the head and body ; hind-limb reaching to beyond the tip of the snout ; lateral and occipital scales intermixed with larger ones. This form ranges over the rest of India and Ceylon. The typical form is from Pondicherry, and Gunther's minor, from Madras, is, therefore, a synonym of it. Ebanasar J. 1989. Histomorphology of thyroid gland in a ground lizard Sitana ponticeriana. M.Sc Dissertation submitted to Madurai Kamaraj University.

Distribution

India from the base of the Himalayas to Cape Comorin, and from the Punjab and Kachchh (not Sind) to Western Bengal; Sri Lanka.

Other references

• Cuvier, G. J. L. N. F. D.
  Georges Cuvier
  Georges Chrétien Léopold Dagobert Cuvier or Jean Léopold Nicolas Frédéric Cuvier , known as Georges Cuvier, was a French naturalist and zoologist...
  
   1829 Le Règne Animal Distribué d'après son Organisation, pour servir de base à l'Histoire naturelle des Animaux et d'introduction à l'Anatomie Comparée. Nouvelle Edition. Vol. 2. Les Reptiles. Déterville, Paris, i-xvi, 1-406
• Jerdon,T.C.
  Thomas C. Jerdon
  Thomas Caverhill Jerdon was a British physician, zoologist and botanist. He is best remembered for his pioneering works on the ornithology of India...
  
  1870 Notes on Indian Herpetology. P. Asiatic Soc. Bengal March 1870: 66-85
• Kelaart, Edward Fred 1854 Catalogue of reptiles collected in Ceylon. Ann. Mag. Nat. Hist. (2) 13: 137-140
• Ebanasar J. 1989. Histomorphology of thyroid gland in a ground lizard Sitana ponticeriana. M.Sc Dissertation submitted to Madurai Kamaraj University.