The document describes the characteristics of arthropods. Arthropods have an external skeleton called an exoskeleton made of chitin, jointed appendages, a segmented body plan, an open circulatory system, and a well-developed nervous system. Arthropods make up about half of all described species and are considered the most diverse and successful group of organisms. The three extant subphyla of arthropods are classified based on the number of antennae.

1. Phylum: Arthropoda

2. Phylum: Arthropoda
Arthropods are the joint-legged animals. (arthro = jointed & poda = leg)

3. Characteristics…..
1. an external skeleton called an exoskeleton that
supports & protects their body. Made of chitin.

4. Characteristics…..
1. an external skeleton called an exoskeleton that
supports & protects their body. Made of chitin.

5. Characteristics…..
1. an external skeleton called an exoskeleton that
supports & protects their body. Made of chitin.
2. Jointed appendages (tentacles, setae, etc. were not
jointed).

6. Characteristics…..
1. an external skeleton called an exoskeleton that
supports & protects their body. Made of chitin.
2. Jointed appendages (tentacles, setae, etc. were not
jointed).

7. Characteristics…..
1. an external skeleton called an exoskeleton that
supports & protects their body. Made of chitin.
2. Jointed appendages (tentacles, setae, etc. were not
jointed).
3. Metameric (segmented) body plan, like their annelid
ancestors.

8. Characteristics…..
1. an external skeleton called an exoskeleton that
supports & protects their body. Made of chitin.
2. Jointed appendages (tentacles, setae, etc. were not
jointed).
3. Metameric body plan, like their annelid ancestors,
the body is divided into distinct segments.

9. Characteristics…..
1. an external skeleton called an exoskeleton that
supports & protects their body. Made of chitin.
2. Jointed appendages (tentacles, setae, etc. were not
jointed).
3. Metameric body plan, like their annelid ancestors,
the body is divided into distinct segments.
4. Open circulatory system.

10. Characteristics…..
1. an external skeleton called an exoskeleton that
supports & protects their body. Made of chitin.
2. Jointed appendages (tentacles, setae, etc. were not
jointed).
3. Metameric body plan, like their annelid ancestors,
the body is divided into distinct segments.
4. Open circulatory system.
5. Well developed, linear nervous system.

11. Scientists have
described about 2
million species of
organisms. About
1 million of them
are arthropods.

12. Scientists have
described about 2
million species of
organisms. About
1 million of them
are arthropods.
If success is
measured by
species diversity,
arthropods are the
most successful
organisms!

13. Arthropods
50%
All plants,
fungi,
bacteria, and
all other
animals
Scientists have
described about 2
million species of
organisms. About
1 million of them
are arthropods.
If success is
measured by
species diversity,
arthropods are the
most successful
organisms!

14. Kingdom
Phylum
Class
Order
Family
Genus
Species

15. Kingdom
Phylum
 Subphylum (not quite different enough to
Class be a class, but too similar to
be a phylum of its own)
Order
Family
Genus
Species

16. extinct

17. extinct extant

18. Trilobites were marine arthropods. They are all
extinct and we only know them as fossils.
Subphylum:
Trilobitomorpha

19. The three extant subphyla of arthropods are classified
based on the number of antennae they have.

20. The three extant subphyla of arthropods are classified
based on the number of antennae they have.
Subphylum Chelicerata (zero)

21. The three extant subphyla of arthropods are classified
based on the number of antennae they have.
Subphylum Chelicerata (zero)
Subphylum Crustacea (two)

22. The three extant subphyla of arthropods are classified
based on the number of antennae they have.
Subphylum Chelicerata (zero)
Subphylum Uniramia (one)
Subphylum Crustacea (two)