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Assertion (A). The earliest fossils of a...

Assertion (A). The earliest fossils of amphibia are from devonian and called labyrinthodontia.
Reason (R). Dentine of earliest amphibian fossils was not of folded nature.
(a) A is true but R is false
(b) Both are true R correct explanation of A
(b) both are true but R is not correct explanation of A
(d) both are false

A

A is true but R is false

B

Both true R correct explanation of A

C

both true but R is not correct explanation of A

D

both false.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze both the assertion (A) and the reason (R) provided. ### Step-by-Step Solution: 1. **Understanding the Assertion (A)**: - The assertion states that the earliest fossils of amphibians are from the Devonian period and are called Labyrinthodontia. - The Labyrinthodontia is indeed a group of extinct amphibians that thrived during the Devonian period, which is approximately 390 to 150 million years ago. Therefore, this assertion is **true**. 2. **Understanding the Reason (R)**: - The reason states that the dentine of the earliest amphibian fossils was not of folded nature. - However, the term "Labyrinthodontia" itself refers to these amphibians having a characteristic of folded or maze-like teeth. Thus, the statement that their dentine was not of folded nature contradicts the definition of Labyrinthodontia. Therefore, this reason is **false**. 3. **Conclusion**: - Since assertion (A) is true and reason (R) is false, the correct answer is (a) A is true but R is false. ### Final Answer: (a) A is true but R is false. ---
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