Cambrian explosion

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/cambrian-explosion

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the scientific name?Not applicable to an event; refers to the diversification of Metazoa
2. What is the geological period?Cambrian Period, Early Paleozoic Era
3. Why did animals start building hard shells during the Cambrian?Animals built hard shells, skeletons, and exoskeletons to protect themselves from predators and to support bigger bodies.
4. How did oxygen help animals grow bigger during the Cambrian?Higher oxygen levels in the oceans and air gave animals more energy, letting them grow larger and move faster.

Cambrian Explosion: An interval of rapid evolutionary diversification where most major animal phyla emerged.
Metazoa: The kingdom of multicellular, eukaryotic animals.
Phyla: The highest taxonomic rank below Kingdom, representing distinct fundamental body plans.
Fossil Record: The historical sequence of fossilized remains and traces, providing evidence of past life.