Describe the characteristics and function of parts of a trilobite fossil, and state the geological era it lived in.

Here are the answers to the questions about the fossil:

a) Identification:

• Trilobite

b) Describe the fossil:

• The fossil is an extinct marine arthropod with a distinctive three-lobed body. Its body is divided into three main sections: a cephalon (head), a thorax (segmented middle section), and a pygidium (tail). It possesses compound eyes and a hard exoskeleton.

c) State the size of the pygidium in relation to the cephalon:

• The pygidium is approximately the same size as or slightly smaller than the cephalon.

d) What are the functions of the parts labelled X and Y?

• Function of X (Thorax): The thorax is composed of articulated segments that allowed the trilobite to flex and enroll for protection. Each segment typically bore appendages used for locomotion, respiration, and feeding.
• Function of Y (Compound Eye): The compound eye is used for vision, allowing the trilobite to detect light, movement, and predators in its marine environment.

e) State the Period during which the fossil lived:

• Paleozoic Era (specifically abundant in the Cambrian to Permian periods)