1. Summary

The Cambrian period is part of the Paleozoic Era. The Cambrian period brought change to life on earth with the development of life forms that were multicellular and more complex than previous eras. The Cambrian explosion during this era refers to the rapid growth during this time that is traced back to one common ancestor.

2. Why Watch This Video?

1. Have you ever wondered what life/species were first created on Earth?
2. Would you like to know what the Cambrian Explosion was?
3. Are you curious about early oceanic life like the anomalocarids?

3. Key Terms

Cambrian Explosion – The explosion refers to a quick change in animal life forms that evolved from singular life form to multicellular life forms. It resulted in the appearance of almost all modern animal phyla. Fossil records from this time confirm the diversity of life.

Eumetazoans – Part of the animal kingdom that includes all multicellular forms of life, except for sponges.

Trilobite – An arthropod that lived in the early Cambrian Period and is a documented fossil from this period of time.

4. Loose Ends

There were many Cambrian species.

There are about 20,000 known species in the Cambrian period. This video is specific to trilobites and arthropod marine life. There are thousands of other species from this period that were not highlighted such as, brachiopods and sponges to name a couple.

Why the Cambrian extinction?

The video explores two hypothesises for the Cambrian extinction that provide good information for the viewer to determine what hypothesis is more valid. The reduction of oxygen and global cooling are possibly responsible for the extinction and could be further researched.

Why did multicellular life develop?

Marine life was the most common form of life during the Cambrian period. The evolution from unicellular to multicellular life forms and the cause of this is not clearly identified. The video provides enough insight that the viewer understands this evolution but there is still deeper exploring of this evolution that can be explored.

5. Self-Test Questions