Guide to Animal Classification

Part One Classification Basics

All organisms (living things) are put into groups based on the traits they have in common.

Organisms are grouped and regrouped until every

organism in the group is one of a kind.

There are seven levels of classification (subgroups) for each individual organism:

1. Kingdom 2. Phylum (Division) 3. Class 4. Order 5. Family 6. Genus 7. Species

Names are based on the Latin language, because it is the common scientific language. The Genus and species names are the most specific, and both are used in identifying unique organisms. This system is called binomial nomenclature (two-names). The names are written in italics, with the Genus name being CAPITALIZED and the species name being lower-case. (e.g. Canis familiaris)

The two-word name is called the organism's scientific name. This system helps to avoid communication errors. The science of classifying and naming organisms is called taxonomy. The branch of science that deals with the study of animals is called zoology.

Classification today is based on a six-kingdom system..

How could you separate each kingdom in this cladogram?

1. Bacteria

2. Archaea

3. Protista

4. Fungi

5. Plants

6. Animals

To be classified in the Animal kingdom, five characteristics must be present.

1. It must have many cells.

2. It cannot make its own food. (They eat other organisms.)

3. It must have eukaryotic cells. (They have a true nucleus.)

4. It must move about.

5. It must digest its food.

The presence of a backbone is the first characteristic used in animal classification.

In addition to the presence of a backbone, scientists will

look at the arrangements of the animal's body parts.

symmetry

Most animals have two sides that match.

bilateral symmetry

Some animals have body parts that are arranged in a circle... like the spokes of a wheel.

radial symmetry

Some animals have no definite shape.

asymmetrical

The nine major divisions (phyla) of animals are:

1. Porifera (sponges) 2. Cnidarians (jellyfish, corals, sea anemones) 3. Platyhelminthes (flatworms) 4. Nematoda (roundworms) 5. Annelida (segmented worms) 6. Mollusca (clams, oysters, squid) 7. Arthropoda (insects, spiders, lobster, centipedes) 8. Echinodermata (starfish, sand dollars, sea urchines) 9. Chordata (vertebrates)

Invertebrates • If the animal does not have a backbone, it is called an invertebrate. • Invertebrates make up 95% of all known animal species. • There are eight major groups (Phyla) of invertebrates

Porifera (pore-bearing animals)

Cnidarians (animals with special stinging cells)

Platyhelminthes (worms with flattened bodies)

Nematoda (worms with round, tube-like bodies)

Annelida (worms with segmented bodies)

Mollusca (soft-bodied animals, usually with a shell)

Arthropoda (animals with segmented bodies, jointed legs, and an exoskeleton)

Echinodermata (spiny, leathery-skinned animals)

Ready for the Quiz?

1. How many levels of classification are there? A. Nine B. Five C. Seven D. Too many to count

C. Seven!!!

1. How many phyla of animals are there? A. Nine B. Five C. Seven D. Too many to count

A. Nine!!!

1. How many kingdoms of organisms are there? A. Nine B. Five C. Seven D. Too many to count

B. Five!!!

1. How many species of animals are there? A. Nine B. Five C. Seven D. Too many to count

D. Too many to count!

Next time.....

Part 2 Sponges