Select the correct statement about the evolution of animals from the following options describing early animal fossils and Cambrian diversity.

Introduction / Context:
The evolution of animals is closely studied through the fossil record, especially rocks from the late Precambrian and Cambrian periods. Exam questions often ask you to identify which statements about early animal fossils and the Cambrian explosion are accurate. This question presents several statements and asks you to select the one correct description about the timing and nature of early animal fossils.

Given Data / Assumptions:

• Statement A mentions that the oldest generally accepted large animal fossils are about 565 to 550 million years old.
• Statement B claims that there are no animal fossils before the Cambrian explosion.
• Statement C extends the idea of Cambrian diversity to approximately half the phyla of all living organisms, not just animals.
• Statement D asserts that all the above statements are correct.
• Statement E suggests that animal evolution began suddenly in the Cambrian with no prior history.

Concept / Approach:
To answer correctly, you must know some basic facts about the fossil record. Ediacaran fossils of large, soft bodied organisms from around 565 to 550 million years ago are widely accepted as early animals or close relatives. This supports statement A. However, statement B is too strong because animal like fossils do exist in late Precambrian strata before the Cambrian explosion. Statement C is inaccurate because it exaggerates to half the phyla of all living organisms, including non animal groups. Statement E is also misleading because animal evolution did not begin suddenly in the Cambrian; earlier forms existed. Therefore, only statement A can be accepted as correct in this set.

Step-by-Step Solution:
Step 1: Evaluate statement A: Ediacaran fossils of large, multicellular organisms are dated between roughly 565 and 550 million years ago, so this description is consistent with accepted data.Step 2: Evaluate statement B: It claims zero animal fossils before the Cambrian, which contradicts the known existence of Ediacaran fossils, so this is incorrect.Step 3: Evaluate statement C: It incorrectly generalises Cambrian diversity to half of all living phyla, including plants and microbes, which is not supported by the fossil record, so this is also wrong.Step 4: Because B and C are wrong, statement D (All the above) automatically becomes incorrect.Step 5: Statement E incorrectly suggests a sudden start without any Precambrian history, which is contradicted by Ediacaran fossils, so it is wrong. Only statement A remains valid.

Verification / Alternative check:
Standard biology textbooks describe the Ediacaran biota as the oldest widely accepted assemblage of large multicellular animals, dating to about 565 to 550 million years ago. They also emphasise that the Cambrian explosion accelerated diversification but did not mark the absolute beginning of animal life. This independent description supports statement A while contradicting statements B, C, and E, confirming that A is the single correct statement.

Why Other Options Are Wrong:
Option B is wrong because late Precambrian strata do contain Ediacaran animal fossils, so it is not true that none are found before the Cambrian.Option C is wrong because it stretches the idea of Cambrian diversity to half the phyla of all life, not just animals, which is not an accurate claim.Option D is wrong because it states that all the previous statements are correct, which they clearly are not.Option E is wrong because animal evolution did not start from zero in the Cambrian; earlier simple animals existed in the Precambrian.

Common Pitfalls:
Students sometimes over interpret the phrase Cambrian explosion to mean that there were absolutely no animals before the Cambrian, which leads them to accept statements like B or E. Others may be tempted by answers like All the above without carefully checking each statement. To avoid such errors, treat the Cambrian explosion as a period of rapid diversification, not the first appearance of animals, and always check whether a statement is too absolute or exaggerated.

Final Answer:
The correct answer is: The oldest generally accepted fossils of large animals range in age from about 565 to 550 million years old.