Animal species are, for example, the blackbird, the trout, the lion, the deer, or the blue whale. It is the lowest unit if you want to classify animals logically. The animals of a species can reproduce with each other, i.e. make young. They also have common characteristics that, for example, a blackbird does not have with a trout. Animal species can be grouped into genera, families, orders, and so on.
The oldest classification of animals into species mentions a story from the Old Testament. It tells of how Noah saved the animal species from the great flood on his ark. He took a pair of each animal species with him so that they could breed again later.
Until modern times there was no other system for classifying animals. The scientist Carl von Linné first wrote down a system in the 18th century, i.e. a division into the three kingdoms of minerals, animals, and plants. He refined each realm like the roots of a tree. Some of the scientists after him did it a little differently, which is why it is very difficult to orient yourself.
But you have to be careful anyway: Many people speak of an animal species but do not mean this in the biological sense, but as in colloquial language. You might mean a genus, an order, or a tribe. Butterflies, for example, are not a species but an order. Dogs are not a species either, but a family. There are many such examples.
How does biology classify animals?
In biology, living beings are classified according to their relationship. It used to be thought that the more things living beings have in common, the more closely they are related to each other. But that doesn’t always work. Many animals have one thing in common, for example, that they all live in the forest. Despite this, woodpeckers and the fox are not related.
In the past, therefore, people tried to find out how closely related they were by looking at their physique, their teeth, or similar features. However, today this classification is no longer correct. With the method of genetic engineering, one can determine exactly what is inside each cell. This is a kind of “blueprint” for the body. Since this changed only step by step in the course of evolution, those animals are most closely related and have the most similar “construction plans”. Some of these findings messed up the old systems quite a bit.
What is the classification?
Once the first rough classification has been made, it is broken down more and more finely: living beings are divided into the animal kingdom, the plant kingdom, the fungal kingdom and a few more. The animal kingdom is divided into individual tribes. This is sometimes very complicated and confusing. In many cases, there are only Latin names for it. Here are some animal species as examples and how they are classified, right down to the classes. All of these classes belong to the Vertebrate phylum, to the kingdom of Multicellular animals, and to the domain of Eukaryotes, which are living beings with a true cell nucleus.
The species of domestic cat belongs to the genus of cats, to the family of cats, to the order of carnivores, and to the class of mammals.
The blackbird species belong to the thrush genus, the thrush family, the order songbirds, and the class birds.
The species of the small edible frog belongs to the genus of edible frogs, to the family of real frogs, to the order of anurans, and to the class of amphibians.
The species of sand lizard belongs to the genus of collared lizards, to the family of real lizards, to the order of scaled reptiles, and to the class of reptiles.
The species of trout belongs to the Salmo genus, the Salmon family, the Salmonidae order, and the Bony fish class.
What phyla are there besides the vertebrates?
This includes the vertebrates that we know best but by no means all animals. There are at least two other tribes that are important:
The Roman snail species belongs to the genus of Helix, the family of snails, the order of pulmonary snails, the class of snails, the subphylum of shellfish, and the phylum of mollusks.
The species of wood dung beetle belongs to the genus Anotrotrupes, family Dung beetles, order Beetles, class Insects, and phylum Arthropods. Millipedes, crabs, and arachnids also belong to this phylum.
There are a few more: The earthworm belongs to the annelid phylum. Sea cucumbers and starfish belong to the echinoderm phylum. Corals and Anthozoa belong to the cnidarian phylum. There are a few more tribes that are less well-known.
How to subdivide a tribe?
This is actually the reverse question. You then search in the system not from bottom to top, but from top to bottom. This cannot be fully explained here, but it can be shown with an example:
The phylum of the vertebrates can be divided as above into the classes mammals, birds, amphibians, reptiles, and fish.
The Mammals class includes the following orders: carnivores, insectivores, cetaceans, even-toed ungulates, and others.
The following families belong to the order of carnivores: cats, bears, seals, hyenas, and others.
The cat family includes the following genera: real cats, lynxes, cougars, and others.
The genus of real cats includes the following species: wild cats, including our domestic cats, black-footed cats, sand cats, and others.
This could be continued with all tribes, classes, orders, families, and genera. But that would then take up more space than the whole lexicon put together.