Placoderm

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/placoderm

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?Placodermi (an extinct class within the superclass Gnathostomata)
2. What were placoderms?Placoderms were ancient fish that lived millions of years ago. They had bony armor on their heads and chests and were the first fish with jaws, which helped them catch food better.
3. Why were placoderms important for the oceans?They were the first successful jawed fish, so they changed how marine life worked. Their strong jaws and armor let them become top predators and helped shape the food chain.

Gnathostomes: The group of vertebrates characterized by the presence of jaws.
Dermal Denticles: Tooth-like structures derived from the skin, sometimes found in placoderm jaws.
Index Fossils: Fossils of organisms that were widely distributed geographically and occurred during a specific time interval, used for dating rock layers.