Mammals
Mammal Characteristics
· All mammals are warm blooded.
· All mammals have lungs to breathe air.
· Mammals feed milk to their babies.
·
Most mammals give birth to living young, except for the platypus and the spiny anteater. They are hatched from eggs.
·
Mammals grow hair or fur. Hair and fur serves as insulation, protection and can be a water repellent
·
Every mammal is a vertebrate. That means mammals have a skeleton with a backbone.
What makes a mammal a mammal and not another kind of animal
If the mammal
is a female can produce milk to feed its young. This milk is produced by modified sweat glands called 'mammary' glands. It
is from these glands that the whole group takes its name, 'Mammals.
No other animal
has hair in the same form as mammals, and all mammals have some hair at least at the beginning of their lives - baby whales
and dolphins are born with a moustache.
The lower jaw
in mammals is a single bone on either side. In all other vertebrates there are more than one bone on each side of the jaw.
The mammal middle ear, and only the mammal middle ear, contains 3 bones. The Stapes or (Stirrup), Incus or (Anvil) and
the Malleus or (Hammer). Once these bones were part of the lower jaw, but during the early evolution of mammals they changed
jobs and became a part of our hearing apparatus instead.
In mammals the main artery leaving the
heart curves to the left becoming the aortic arch. In birds it curves to the right and in all other vertebrates there are
more than one main artery leaving the heart.
Mammals have
a diaphragm which is a sheet of muscle and tendon that separates the body cavity into two sections. Heart and lungs before/above,
liver, kidneys, stomach, intestines, etc, behind/below. No other animal has a diaphragm.
Mammals are
warm blooded.
Fact: There
are about 4260 named species of mammal in the world. But more will be discovered.
Mammals may have only become successful as a group relatively
recently, but they have been around a long time. The first mammals appeared about 265 million years ago.
Did you know??
Nearly a quarter
of all mammals can fly, approximately 985 species of mammal.
Mammals are animals that have hair, are warm-blooded, and nourish their young with milk. Some modern-day mammals include people,
apes, cats, bats, dogs, tigers, mice, moose, aardvarks, beavers, elephants, gorillas, sloths, pandas, hamsters, horses, whales, and dolphins.
Types of Mammals
Monotremes: The monotremes are primitive egg-laying mammals. Modern-day monotremes include the echidnas which are spiny ant-eaters and the duck-billed platypus.
Marsupials: Marsupials are another group of mammals; their young are born in an extremely immature state; most female marsupials have
pouches. Some marsupials include the koala, kangaroo, and the numbat.
Placental mammals: Placental mammals are mammals whose young are born at a relatively advanced stage (more advanced than the young of other mammals, the
monotremes and marsupials). Before birth, the young are nourished through a placenta. The placenta is a specialized embryonic
organ that is attached the mother's uterus and delivers oxygen and nutrients to the young. Most mammals are placental mammals,
like cats, dogs, horses, and people.
Mammal Extremes
- Fastest
mammal (also the fastest land animal): the cheetah (60-70 mph = 97-110 kph)
- Slowest
mammal - the sloth (less than 1 mph, or 2 kph)
- Biggest
mammal, biggest animal that ever lived on Earth - the blue whale
- Biggest
land mammal- the African Elephant
- Tallest
mammal - the giraffe
- Smallest
mammals - the pygmy shrew (weighing 1.2-2.7 gm) and the bumblebee bat (weighing about 2 gm)
- Loudest
mammal - the Blue Whale. The second loudest is the Howler Monkey.
- Smallest
newborns - marsupials (pouched mammals, like the kangaroo)
- Smelliest
mammal - the striped skunk (Mephitis mephitis)
