Animal Taxonomy

There are more than a million of species of animals on Earth. These animals are grouped according to their similarities and differences. Their classifications are based on their characteristics, general structure, development, distribution, evolutionary relationships, and adaptations. The branch of biology that deals with the classification and naming of different organisms is called taxonomy.

Animals are classified into two major groups based on the presence or absence of vertebrae, the bony segments that protect the spinal cord. These two groups are the vertebrates and the invertebrates. Vertebrates have vertebrae while invertebrates do not have vertebrae. Vertebrates are distinguished from invertebrates by having an internal skeleton or endoskeleton, a closed circulatory system, paired appendages, functioning respiratory and excretory systems, and a complex nervous system.

Vertebrates and invertebrates are grouped into different phyla which include different classes. These classes include different orders, which include different families. The families are further subdivided into several genera, which are classified into different species. The naming of these animals is based on the binomial system of nomenclature. The genus and species names of animals make up their scientific names.