Summary:
- There are more than a million known species of arthropods.
- Arthropods include insects, spiders, lobsters, and centipedes.
- They range in length from about 1 millimeter to 4 meters (about 13 feet) They have a segmented body with a hard exoskeleton.
- They also have jointed appendages, which may be used as legs for walking.
- They are the largest phylum of invertebrates and have a life cycle with sexual reproduction.
- They lived for at least 200 million years before going extinct.