How Turtle Shells Evolved: Ted Ed Lesson

​Grab a pair of headphones & listen very carefully to the video. You may watch the video as many times as you'd like.

How Turtle Shells Evolved... Twice

Check out the fascinating science behind the evolution of the turtle shell, over 260 million years in the making.

Modern turtle shells are almost as diverse as the turtles themselves. Sea turtles have flatter, lighter shells for gliding through the water. Land-dwelling tortoises have domed shells that can slip free of predators’ jaws. Leatherback turtles have shells without the ring of bone around the edge. So how did the shell evolve?

Multiple Choice

1. What is the main focus of the video?

• a) The different types of reptiles in the Triassic period
  

• b) The evolution of the turtle's shell
  

• c) The swimming habits of Odontochelys semitestacea
  

• d) The importance of protecting oneself from predators

Multiple Choice

2. According to the video, how many carapaces does a modern turtle have?

• a) One
  

• b) Two
  

• c) Three
  

• d) Four

Multiple Choice

3. What is the role of the crête carapace in the development of the turtle's shell?

• a) It attracts cells that become ribs
  

• b) It creates a protective layer over the shell
  

• c) It helps the turtle swim faster
  

• d) It produces the protein that forms the bones of the shell

Multiple Choice

4. How does the turtle breathe without a flexible ribcage?

• a) It uses its abdominal muscles attached to the shell
  

• b) It has special gills to extract oxygen from water
  

• c) It can retract its head into its shell to breathe
  

• d) It doesn't need to breathe because it gets oxygen from its food

Multiple Choice

5. What is the first known ancestor of the turtle?

• a) Eunotosaurus africanus
  

• 
  b) Odontochelys semitestacea
  

• 
  c) Proganochelys quenstedti
  

• d) Anne-Sophie Matichard

Multiple Choice

6. How are the carapaces of modern turtles different from each other?

• a) They have different patterns and colors
  

• b) They have different numbers of bones
  

• c) They have different shapes and sizes
  

• d) They have different types of scales

Multiple Choice

7. What advantage do tortoises have with their domed shells?

• a) They can camouflage better in their environment
  

• b) They can swim faster in the water
  

• c) They can protect themselves from predators
  

• d) They can fly in the air