Name the first one-toed horse.

Options

A. a) Pliohippus
B. b) Eohippus
C. c) Mesohippus
D. d) None of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of the first one-toed horse. This requires knowledge of horse evolution and the specific species that represent the transition to a single-toed structure.

2. **Identifying the Options**: The options provided are Cleohippus, Eohippus, Mesohippus, and none of these. We need to analyze each option to determine which one corresponds to the first one-toed horse.

3. **Evolution of Horses**: Horses have evolved over millions of years from multi-toed ancestors to the modern single-toed horses we see today. The single toe is a result of evolutionary adaptations for better running.

4. **Analyzing Each Option**:
- **Eohippus**: Known as the "dawn horse," it is considered the first horse but had multiple toes and lived around 60 million years ago.
- **Mesohippus**: This horse lived approximately 30 to 40 million years ago and also had multiple toes.
- **Cleohippus**: This is the correct answer. Cleohippus is recognized as the first one-toed horse, having evolved around 5 million years ago in North America.

5. **Conclusion**: Based on the analysis, the first one-toed horse is **Cleohippus**.

**Final Answer**: Cleohippus

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