Classification into species

The groups or kingdoms are very broad categories. However, the living creatures can also be further classified. Scientists have defined so many subgroups that only one type of organism was left: the species. The classification of the classical taxonomy (= classification into systematic categories) was based on the similarity of the organisms, e.g. how many characteristics they have in common. The modern taxonomy additionally regards the history of organisms, so that sometimes contradictory classifications are found.

In order that the students are able to understand the systematic of the classifications the examples given below are based on the classical taxonomy, which can be understood on the basis of external similarity. However, only for the example Tyrannosaurus rex there was a discrepancy between the taxonomies.