Why is the fossil record of clams more complete than that of spiders?

• A. Clams reproduce more rapidly, increasing their chances of fossilization.
• B. Spiders live in aquatic environments where fossilization is less likely.
• C. Spiders are more likely to be eaten before they can fossilize.
• D. Clams have hard shells that fossilize more easily than the soft bodies of spiders.

Answer: (D)

Verified step by step guidance

1. Understand the process of fossilization: Fossilization typically occurs when an organism is buried quickly after death, and its remains are preserved under layers of sediment. Hard parts like shells, bones, and teeth are more likely to fossilize because they resist decay and decomposition better than soft tissues.
2. Compare the physical structures of clams and spiders: Clams have hard shells made of calcium carbonate, which are durable and can withstand environmental pressures over time. Spiders, on the other hand, have soft bodies and exoskeletons made of chitin, which decompose more rapidly and are less likely to fossilize.
3. Consider the environmental factors: Clams often live in aquatic environments where sediment deposition is frequent, increasing the likelihood of burial and fossilization. Spiders, however, are primarily terrestrial and less likely to be buried in sediment quickly after death.
4. Evaluate the biological differences: The reproductive rate or likelihood of being eaten before fossilization does not directly impact the completeness of the fossil record. Instead, the physical composition of the organism plays a more significant role in determining fossilization potential.
5. Conclude that the hard shells of clams make them more likely to be preserved in the fossil record compared to the soft bodies of spiders, which decompose more easily and are less likely to fossilize.