Uromastix or Sand Lizard

Uromastix or Sand Lizard

Uromastix or the spiny tailed lizard, also known as sand lizard, occurs throughout North-Western India up to UP. It is usually found in the sandy tracts where vegetation is scanty. It is a burrowing animal and the burrow is dug by the powerful claws of the limbs. The burrows are usually dug near shrubs. Each individual lives in its own burrow. Uromastix does not leave the burrow until the sun is up. After feeding, it returns to its burrow. At night it closes the entrance to the burrow. During the day it feeds on grass, flowers and fruits. It may feed on insects also. Uromastix is slow in its movement and has a gentle disposition. It can be tamed soon in captivity. When disturbed it lifts its head in a characteristic way and opens its mouth at the same time to frighten away the disturber. It uses its spiny tail to protect itself from snakes. The breeding season starts in March and April in Northern India. Copulation is preceded by some sex play. Generally, copulation takes place in between 10 AM to 3 PM in the open sun in clear summer days. During copulation only one hemipenis at a time is inserted into the cloaca of female. The female lays 10 – 15 eggs in the burrow. The warmth of the surroundings helps the development of the eggs. Development of eggs takes place by the warmth of the surroundings. Some tribes in the hilly regions of Rajasthan take it as food. The tail is considered to be a delicacy. The oil obtained by boiling its fat is used as embrocation and as a cure for impotency.

It is a medium size lizard with a massive body which is depressed dorsoventrally. The body is covered with small scales. The long and thick tail tapers posteriorly and is provided with rings of spinose scales. The colour of the body is yellowish-brown above and pale yellow. Dark spots are seen on the dorsal surface of the body. Large blackish spots are present on each thigh and throat. The body is divisible into three parts –

1. Head,

2. Trunk and

3. Tail.

The head is small and triangular. There are two large apertures, the nostrils at the anterior extremity of the head. On each side of the head is present a large eye provided with two movable eyelids. A transparent nictitating membrane is also present. A wide slit-like mouth runs along the anterior border of the head. Behind the eye on each side is present a depressed, circular brown patch of skin, the external auditory meatus. Its anterior border is somewhat denticulated. The head is followed by a short neck. Skin of the neck and sides of the body are very loose with more or less distinct transverse folds across the throat. The neck continues behind into a broad and depressed trunk. The elongated trunk is convex dorsally, but flattened ventrally. It is supported by two pairs of well-developed limbs. Each forelimb consists of the upper arm (branchium), the forearm (anti-branchium) and the hand provided with five clawed digits. The tail is thick and dorsoventrally compressed. It is wide near the base and gradually tapers posteriorly. There are about 20 transverse rows of spinose scales. The rows of spinose scales are separated from one another by 4-6 rows of keeled scales. The under-surface of the tail is covered with large or squarish scales.

The skin of Uromastix is covered with scales which more or less overlap one another. The size and arrangement of scales differ in different parts of the body. Upper head scales are unequal, smooth or obtusely keeled. The scales on the cheeks are oval. There are 12-14 upper labials which are more or less denticulated on their free margins. Dorsal scales are very small, sub-equal and mostly smooth. The ventral scales are sub-quadrangular in shape. Gular scales are rounded. The horny epidermal coating of skin is shed off at intervals. The heart of Uromastix is a triangular structure which lies enclosed within a thin, membranous and transparent pericardium.

Reference

1. Britannica Reference Encyclopaedia

2. Knowledge Encyclopedia Animal!: The Animal Kingdom as you've Never Seen it Before

3. Images are taken from Zoo-Que and Google.

4. In Defense of Plants: An Exploration Into the Wonder of Plants

5. A Naturalist’s Guide to the Birds of India

6. Earth: A Sustainable Planet

Also See

• Migration & Navigation of Birds

• Archaeopteryx – The First Bird`s Fossil

• Parrots

• Bats