Geographical distribution: Distributed in Australia, Tasmania and New Guinea.
Habit and habitat : It is terrestrial burrowing and nocturnal. Feeds on ants.
Comments:
1. Commonly called as Spiny Anteater. Body divisible into head, neck and trunk.
2. Externally the neck and body are indistinct and covered with strong pointed spines. Coarse hair lies at the base of spines. Lower surface has only hairs, no spines
3. Head small and produced into a small tubular pointed snout. Containing eye and nostril.
4. Eyes small, without nictitating membrane. External ears absent. Tongue long and sticky. Teeth are absent in adults.
5. Girdles forelimbs and hind limbs are reptile-like. Feet without the web. Sharp claws used for digging the earth and nests of insects.
6. Second digit of the hind limb has a long and curved toilet claw to clean spines. Tarsus of male has a grooved horny poison spur.
7. Male also possesses mammary glands secreting milk and this condition is called as gynaecomastisus, where both parents nourish young one. Teats absent.
8. Mammary glands open inside a ventral abdominal pouch by several apertures. Eggs transferred by mother into the pouch where the young are nourished with milk.
9. In defensive position Echidna rolls in such a manner that bilateral barrier of spines completely cover it.
Special features: Echidna has phylogenetic significance, as it serves a link between reptiles and mammals. The animal is specialized for ant eating . The jaws are pointed forming a rostrum devoid of any teeth. Tongue is protrusible. The posterior region of the tongue is serrated to grind insects and the secretion of salivary gland neutralizes formic acid and ants.
Source:
1. Practical Zoology Vertebrates by S.S.Lal. 2. A Manual of Practical Zoology Chordates by Dr. P.S. Verma.
