How do birds differ from mammals?

The question of the week: what classes of animals are there besides mammals and how do they differ?


In our archive you will find the most popular texts and children's questions from 15 years Click into your favorite topics!

The question of the week: what classes of animals are there besides mammals and how do they differ?

Every week we answer your questions on all kinds of topics. Today Felix from Lorch asks us: "What classes of animals are there besides mammals and how do they differ?" Here's the answer ...

Our world is very diverse and is home to many different lives. So that we don't lose the overview, there is a special system with which one tries to order all life in order to better distinguish organisms from one another.

Think of this attempt at classifying living things as a large closet with different drawers. In these drawers there are all sorts of living beings, but they are similar in one or the other feature.

All living beings are at the very beginning of this system. This generic term includes, so to speak, all existing animals, plants, fungi and microorganisms.

Below is the domain. All living beings are divided into three domains. Science differentiates here between bacteria, archaea and eukaryotes.

Bacteria and archaea are known as prokaryotes because of their cell structure. Their cells do not have a nucleus and their domain is divided into strains.

The eukaryotes, on the other hand, have a nucleus and are divided into realms beforehand. There are again three levels of subdivision: the animal kingdom, the vegetable kingdom and the mushroom kingdom. Then the eukaryotes are also divided into tribes.


The chordates, for example, are a tribe of the animal kingdom. All animals in this strain have certain similarities, some of which can only be seen clearly in the larval or embryonic stage.

For example, all chordates have a heart on the stomach side that pumps the blood forward to the head. Animal phyla can also be divided into sub-phyla.

The sub-tribes of the chordates are the vertebrates, the tunicates and the skullless. Another tribe is, for example, that of the arthropods.

But that is far from being the end of it. After differentiating certain tribes, one further subdivides into classes.


The vertebrates are separated into fish, amphibians, reptiles, birds and mammals, for example. In the case of arthropods, a distinction is made between insects, millipedes, crustaceans, arachnids and an extinct species, the trilobites.

Each class has specific characteristics that clearly distinguish it from the other classes within its tribe.

Mammals differ from animals from other classes in that their offspring are suckled with milk, they have a fur made of hair and a body temperature of the same temperature, which makes them relatively independent of the ambient temperature.

Even if certain mammals such as whales do not have fur, at least their ancestors did. In addition, whales in the embryonic stage have a short coat of hair.

Again, it is further divided into subclasses. The mammals are divided into three subclasses: the mammals, the marsupials and the higher mammals.


The next level of distinction is order. Mammals, like birds, are divided into about 30 orders. Amphibians only have three different orders.

This classification continues with all other animal classes. In mammals, for example, all whales form one of the approximately 30 orders. Another order of mammals is that of predators. These include both the canine and the feline.

Another order, for example, is the arachnid scorpions.


Within the order of the carnivores, the canine species form a superfamily. Within this superfamily, the canines are divided into the following families: dogs, bears, walruses, ear seals, dog seals, small pandas, skunks, small bears and martens.

The defining characteristics that the animals within these families possess are a pointed snout and non-retractable claws.

The feline are also a superfamily, which are divided into three subfamilies: the cheetahs, the big cats and the small cats.

The most important differentiating criteria in this subdivision are the morphology of the claws, which are not retractable in cheetahs, and on the other hand the structure of the hyoid bone, which is elastic in large cats and ossified in small cats.

Another family, for example, is that of the dolphins.


The genus forms the penultimate level of this order. The often incomprehensible names of animals are particularly important here.

For example, the lion is called Panthera leo, the leopard Panthera pardu, the tiger Panthera tigris, the snow leopard Panthera uncia and the jaguar Panthera onca.

It is noticeable that the first name always remains the same, whereas the second word changes. This very first word is the genus.

The genus Panthera (panther-like) belongs to the family of big cats and includes different animal species.

Animal species

The lowest level is that of the animal species. Here one always refers to a very special animal species. For example, the lion, the tiger, the wolf, or the bottlenose dolphin, a species of dolphin known from television ("Flipper").

Text: RR, as of October 20, 2011, Graphic: Peter Halasz (cc by sa 3.0), Photos: Michael Haferkamp (polar rabbit; cc by sa 2.0), Photodisc (polar bear), (skunk; PD), Manfred Werner (panda; cc by sa 3.0)

Note: All images and links have been removed from the archive