Classifying Living Things

There are millions of organisms on Earth. Animals, plants, bacteria, fungi and more!

They live in every location from the deepest seas to the highest mountain. Some organisms look alike. Others are hard to place in one group or another.

And just using a "common name" doesn't always work.

Example: What is a Buzzard?


In Europe a "buzzard" looks like this.






In the USA a "buzzard" looks like this:

It is a bird that feeds on dead animals.






So just saying "Buzzard" is not good enough!

So a better system is needed.


The first individual to really organize a naming system was Carl Linnaeus (1707-1778). He created a system that used category called a "taxon".

There were seven taxonomic categories:

  • Kingdom (such as the "Animal Kingdom")
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species

They help scientists organize all living things on Earth.

The top one (Kingdom) is the most general (largest grouping), then it gets more and more specific (smaller and smaller groups).

Classifying organisms into groups is known as taxonomy.


It is often enough to just use the genus and species together:

Example: the Gray wolf is called Canis lupus

Its full list of taxons is:

  • Kingdom: Animalia ("Animal Kingdom"))
  • Phylum: Chordata (roughly meaning animals with spinal chords)
  • Class: Mammalia ("Mammals")
  • Order: Carnivora ("Carnivores")
  • Family: Canidae (includes dogs, wolves, foxes, jackals, coyotes)
  • Genus: Canis ("Canines")
  • Species: lupus ("Wolf")

This "two word" naming (using Genus species) is called binomial nomenclature.

Sometimes a "Subspecies" is also used:

Example: the domestic dog is Canis lupus familiaris


(Because dogs are a subspecies of the Gray Wolf)





The words are written in Latin because Latin is a "dead" language, so it will not change or add new words. This ensures the names given to organisms will not change as they could with a living language.

Writing the name:

The first letter of the genus name is a Capital letter, and the first letter of the species name is in lowercase. Both words should be in italics.

So: Canis lupus (not Canis Lupus or canis lupus or Canis lupus.)

Here are a few more examples:

Example: The Brown bear is Ursus arctos

Its full list of taxons is:

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Mammalia
  • Order: Carnivora
  • Family: Ursidae ("bears")
  • Genus: Ursus
  • Species: arctos

Notice that the Brown Bear and Gray Wolf are both members of the Order Carnivora.

Example: This is an example of Rosa chinensis:

Its full list of taxons is:

  • Kingdom: Plantae ("Plants")
  • Phylum: Tracheophyta
  • Class: Magnoliopsida
  • Order: Rosales
  • Family: Rosaceae
  • Genus: Rosa
  • Species: chinensis

Organized organisms

By using this system, we ensure that we are talking about the correct organisms in science. It is a universal system of naming that all scientists around the world can use.

It helps to link organisms together by what they have in common.

It is also in place for any new organisms that are discovered.