What do you mean by extinct species?

Explanation

**Step-by-Step Text Solution:**

1. **Definition of Extinct Species**: Extinct species refer to those species that once existed on Earth but no longer exist today. This means that they have completely vanished and cannot be found anywhere in the world.

2. **Characteristics of Extinct Species**: Extinct species are characterized by their total disappearance from the planet. This means that there are no living individuals of that species left, and they cannot be revived or found again.

3. **Causes of Extinction**: The extinction of species can occur due to various reasons, including habitat loss, deforestation, climate change, and human activities. These factors can lead to a decline in population and ultimately result in extinction.

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