Arthropods

The arthropods are the most successful type of organism known so far - if you define success by the number of known species. Almost half of the described species are arthropods, and given the rate at which scientists find new species, we can presume that we have described less than one fifth of the species out there. They are bilaterally symmetrical (there is a left/right symmetry), their bodies are made up from a series of segments, and they have paired and usually jointed appendages on some or all of the body segments. The body is protected by a tough organic or organic-mineral cuticle which functions as an exoskeleton. In order to grow, arthropods periodically shed their cuticle by a process called ecdysis. Insects, spiders, crustacea, trilobites are all types of arthropods.

Marine Arthropods: A Successful Design Video and Lesson Plans

More Resources About Marine Arthropods

Terrestrial Arthropods: The Conquerors Video and Lesson Plans

More Resources About Terrestrial Arthropods

About Shape of Life

Shape of Life is a series of FREE classroom videos based on an original PBS Series. Explore the beautiful evolution of the animal kingdom on planet earth. The series is NGSS aligned with exquisite focus on diversity, biodiversity, adaptability, body structure, design, behaviors, and the innovative scientists who explore these creatures.

The Arthropod Story. Understanding Evolution. University of California Museum of Paleontology (UCMP).