The Cambrian explosion gave rise to organisms that ate other organisms. Which of the following adaptations from these organisms (recreated from fossils) DOES NOT indicate this fact?

Question

The Cambrian explosion gave rise to organisms that ate other organisms. Which of the following adaptations from these organisms (recreated from fossils) DOES NOT indicate this fact?

A. Marrella has antennae for sensing dead material on the ocean floor.

B. Aysheaia has claws likely used for climbing on sponges.

C. Hallucigenia has spines.

D. Pikaia has a chordate (backbone) used swimming away from predators.

E. Opabinia has eyes.

Answer 1

The answer is E. Opabinia has eyes.

This answer is very general and does not directly suppprt the fact of organisms eating other organisms. However, all of the other answers support the fact of organisms eating other organisms.

A. This answer mentions an organism sensing dead organisms. The dead organisms will be eaten. This supports the fact of an organism eating other organisms. 

B. This organism climbed sponges to eat the sponges. This supports the fact of an organism eating other organisms.

C.The spines on this organism are a defense to protect them from being eaten. This supports the fact of an organism eating other organisms.

D. This fact states that an organism swam away from predators so it would not be eaten.

Answer 2

Answer: E. Opabinia having eyes does not necessarily indicate that it ate other organisms. While having eyes could certainly be an advantage for predators, they could also be useful for prey species to detect predators and avoid being eaten. The other adaptations listed, such as antennae for sensing dead material and claws for climbing, are more directly related to obtaining food or avoiding becoming food.