Questions for ‘Living Mysteries: Meet Earth’s simplest animal’


Dickinsonia was one of the first animals on Earth. It lived on the ocean floor 550 million to 560 million years ago. It looked like a giant version of the modern-day Trichoplax, the simplest animal now alive.

John Sibbick

To accompany feature “Living Mysteries: Meet Earth’s simplest animal


Before Reading

1.  What do you know about how animals on Earth have evolved?   

2.  How might learning about the traits of one kind of animal help scientists understand something about animals that are very different?    

During Reading:

1.  Who was Franz Eilhard Schulze, and what is he best remembered for, according to this story?     

2.  What does the name Trichoplax adhaerens mean? What is special about this animal?  

3.  Describe the shape of the Trichoplax’s body. How does it move?

4.  What does Trichoplax eat?

5.  According to Bernd Schierwater, what clues does the Trichoplax offer for understanding how the first animals might have evolved?    

6.  What did Schierwater and his colleagues learn when they sequenced Trichoplax’s genes in 2008?            

7.  What are two examples of Trichoplax genes that play important roles in shaping animals’ bodies?   

8.   According to the story, what are gland cells, and how do they control the behavior of Trichoplax?  

9.   What type of cells are Carolyn Smith and Thomas Reese studying in the Trichoplax nervous system? What do they think these cells do? 

10.  According to a 2009 study, Trichoplax has a special way of defending itself against predators. How does it do that?

After Reading

1.  Scientists are still learning a lot about Trichoplax today, more than a century after it was first discovered. Given how simple this animal is, what are some reasons it might still be surprisingly hard to understand?

2.  Imagine that you were cleaning out a fish tank when you discovered a tiny animal that you’d never seen before. It might become your claim to fame (or one of them, anyway). What types of things might you want to figure out about this organism? What type of research might you undertake to answer those questions?