Evolution of cetaceans

High school (ages 12+)
Animals & Nature

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/evolution-of-cetaceans

1. What is the scientific name?
2. What is the geological epoch of origin?
3. What did whales and dolphins look like when they first started living in water?
4. Why do whales and dolphins still have five fingers on their flippers?

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?Cetacea
2. What is the geological epoch of origin?Eocene (approximately 56-34 million years ago)
3. What did whales and dolphins look like when they first started living in water?When whales and dolphins first started living in water, they still had hind legs and their noses were on the top of their skulls, showing they were moving from land to sea.
4. Why do whales and dolphins still have five fingers on their flippers?Their flippers still have the same five bones that land animals use for fingers, which shows they came from animals that walked on land.

Artiodactyla: An order of even-toed ungulate mammals, including hippos, deer, cattle, and cetaceans.
Archaeocetes: An extinct suborder of primitive, mostly marine cetaceans representing transitional forms from land to sea.
Baleen: Keratinous plates in the mouths of Mysticeti used for filter-feeding on plankton and small organisms.
Echolocation: A biological sonar system used by Odontocetes for navigation, communication, and prey detection.