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Date & Time : 22, December 2024 17:21
General Characteristics of Mammalia
- skin is covered by hairs.
- external ears (pinnae) are present.
- skull with two occipital condyles, and no prefrontals, postfrontals and quadrato-jugal.
- The lower jaw is composed of single bone on each side.
- the digits are not more than five digits.
- Red blood cells are non - nucleated.
Classification of Mammalia
A Few Examples
1. Sorex
Common name-Shrew.
Distribution-found in Asia, Europe and North America.
Habit and habitat-lives in tunnel
Food- insects, worms and mice.
IDENTIFYING CHARACTERS-
- Body- Rat like, and is covering with fur.
- Body length-12.5 cm including the tail.
- Body color- brown and pale.
- elongated snout while eyes and ears are small.
- Teeth-red in color, lower canines are absent and first pair of insisors is long.
Dental formula is
i 3/2
c 1/0 =32
pm 3/1
m 3/3
- Limbs- limbs are consist of 5 clawed-digits.
- It eat food twice as much as food as their weight. Shrew can not live withoout food more than ten hours.
2. Erinaceus
Common name- Hedge hog
Distribution- found in North India.
Habit and habitat- nocturnal in habitat, lives in holes.
Food- insects, worms, slugs, fruits and roots etc.
IDENTIFYING CHARACTERS-
- Body- back and sides are covered with spines but the ventral surface is covered with soft fur.
- Eyes and ear- small, but pinna is present which is also very small.
Dental formula is
i 3/2
c 1/1
pm 3/2
m 3/3
- Ribs- fourteen or fifteen.
- Tail- it is very short. twelve rib is present in the tail.
- The animal has the habit of rolling itself into a ball when it seems to be in danger.
3. Scotophilus
Common name- bat
Distribution -cosmopolitan in distribution
Habit and habitat- nocturnal in habit.i.e. sleep in day and comes out in night in search of their food.
Food- blood of other animals.
IDENTIFYING CHARACTERS-
- integument- covered with soft fur.
- Snout- short and no nose leaf.
- Ear- ear with large pinna providing with flags. high power of hearing.
- Eyes-small, rods are not properly developed therefore, vision is very weak.
- Teeth- molars have transverse groove.
- Limbs-in the forelimbs , only thumb is clawed. but in hindlimbs, all digits are clawed.
- Tail- it is included in the inter femoral membrane consistinfg of a flap.
- It likes to livein colonies.
- When it strike to any object, it produce ultra sonic sound waves.
4. Talpa
Common Name- short tailed mole.
Distribution- found in the central and western Himalayas and Assam hills.
Habit and Habitat-burrowing animal, lives underground in burrows.
Food- earthworms etc.
IDENTIFYING CHARACTERS
Body-cylindrical.
Integument- covered with silky fur.
Head- short and conical.
Eyes- very small.
Teeth- 40 in number.
Limbs-fore-limbs are well developed, consisting of claws.
Ear- pinnae are absent.
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