Why aren't birds classified as mammals?

Answer 1

There are several characters that are shared by all mammals:

The biggest, most diagnostic, definitive characters are:

- 3 inner ear bones (birds have only one)
- Mammary glands (birds do not have)
- Pelage consisting of keratin hair (birds have feathers)

Other characters include:

- External pinnae (ears - birds do not have external ears)
- Muscular diaphragm between thorasic and abdomenal cavities (birds do not have)
- Left aortic arch (in birds, it is to the right)
- Enucleated erythrocytes (red blood cells without nuclei - birds have nuclei in their red blood cells)
- Single dentary bone (birds have more than one bone in the lower jaw)
- Jaw joint is between dentary/squamosal bones (birds, like reptiles have the jaw joint between quadrate and articular)

Note that neither live birth, nor endothermy are diagnostic characters for Class Mammalia. Some mammals (living and fossil) can and do lay eggs, and endothermy is a derived character that birds and mammals both developed independently (probably).

Answer 2

The biggest reason is that birds do not produce milk. All mammals produce milk. Birds have feathers and mammals do not. These are really the two main ones without getting really technical.

And egg laying does not separate birds from mammals. There are a group of mammals that lay eggs. There are only a few species that I know of that are in this group. The duck-billed platapus and echidnas are two of the more well known ones.

Answer 3

All mammals must have some sort of mammary glands, which produce milk for their young. When the platypus was discovered, scientists had a very hard time classifying it, since it laid eggs, was warm blooded, and seemed to lack mammary glands. However, they later found out that it secretes milk through it's fur (or maybe it's skin, I don't remember), hence making it a mammal. Before chicks are able to eat bugs, the mother bird actually does almost give milk to her young. She has a milky fluid which she gives to her young through her mouth. It's not actual milk, so it doesn't count, though. Anyway, I think that's why.

Answer 4

Mammals suckle their young from breasts, breasts are called mammary glands to produce milk, but birds do not, Each major group of animals have similar characteristics. All reptiles have scales and are poikilothermic (cold-blooded), All fish are pokilothermic, live in water, use gills but we break the groups further, as with fish we have Osteoichthys(Bony fish) and Chrondoichthys (cartinlagineous fish).. Man is a mammal and shares characteristics with monkeys and apes and is know as a primate.

Answer 5

Mammals are called such because they give milk.
The word stems form the latin 'mammalis' meaning "Of the breast"

A Mammal is defined as any of a class (Mammalia) of warm-blooded higher vertebrates that nourish their young with milk secreted by mammary glands, have the skin usually more or less covered with hair.

Birds are warm-blooded vertebrates, but they have neither milk nor hair.

Answer 6

The kiwi is a chook, ultimate. it quite is flightless and has very small unnoticeable stubs for wings. Nostrils based on the tip of the Kiwi's long bill are used for searching for prey mutually as probing undergroiund interior the airborne dirt and dust around the recent Zealand bush. No, the Kiwi isn't on the subject count of a mammal - its in simple terms that the nostrils on the tip of the beak make this chook stand out as a mamillian characteristic.

Answer 7

Mammals are viviparous[they give birth to young ones]. This is the main fact for not including birds in this group.

Answer 8

Well, first of all, mammals have mammary glands, or breasts which dispense milk to their young. Birds do not have breasts with nipples for suckling their young.
Mammals give live birth after carrying their young for a gestation period inside of them (pregnancy). Birds lay eggs and nest them.

Answer 9

Mammals = fur, live babies at birth, nourish with milk, warm-blooded, usually on all fours.

Avian (birds) = feathers, birth to eggs, always on two legs with a pair of wings, beaks.

Answer 10

they dont create milk,you see there are a some mammals that lay eggs ie;the platypus.there are also non mammals that birth live young ie;sharks also the feathers arent fur thing