The extinction of dinosaur took place

Options

A. before the origin of seaweeds.
B. before the origin of first amphibian.
C. when the rise of modern fishes, birds , and placental mammals were seen
D. after the the origin of turtles .

Answer

To determine when the extinction of dinosaurs took place, we can follow these steps:

### Step 1: Identify the Timeframe of Dinosaur Extinction
- Dinosaurs are known to have gone extinct approximately 65 million years ago, at the end of the Cretaceous period.

### Step 2: Analyze the Options Given
- **Option 1: Before the origin of seaweeds**
- Seaweeds originated much earlier, around 320 million years ago during the Ordovician period. Therefore, this option is incorrect.

- **Option 2: Before the origin of first amphibians**
- Amphibians began to evolve during the Upper Carboniferous Period, which is also earlier than the extinction of dinosaurs. Thus, this option is incorrect.

- **Option 3: When the rise of modern fishes, birds, and placental mammals were seen**
- This option is correct. The rise of modern fishes, birds, and placental mammals occurred during the Cenozoic era, which began after the extinction of dinosaurs. The extinction coincided with the transition from the Cretaceous to the Cenozoic era.

- **Option 4: After the origin of turtles**
- Turtles originated before the extinction of dinosaurs, making this option incorrect as well.

### Step 3: Conclusion
- Based on the analysis, the correct answer is **Option 3**: The extinction of dinosaurs took place when the rise of modern fishes, birds, and placental mammals were seen.

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