What is the correct sequence of the evolutionary stage of horse
a. Mesohippus b. Eohippus
c. Equus d. Merrychippus
e. Pliohippus

Answer

To determine the correct sequence of the evolutionary stages of the horse, we can follow the lineage of horse evolution as documented in paleontology. Here’s the step-by-step solution:

### Step-by-Step Solution:

1. **Identify the Earliest Ancestor**:
- The earliest known ancestor of the horse is **Eohippus**, also known as the "Dawn Horse". It appeared during the early Eocene epoch, which lasted from about 56 million to 33 million years ago.

2. **Next Evolutionary Stage**:
- After Eohippus, the next significant ancestor is **Mesohippus**. This species emerged during the early and middle Oligocene epoch. Mesohippus was more horse-like compared to Eohippus.

3. **Following Evolutionary Stage**:
- The lineage continues with **Merychippus**, which evolved from Mesohippus. Merychippus appeared during the late Miocene epoch and was a significant step towards modern horses, adapting to grazing.

4. **Further Evolution**:
- Next in the sequence is **Pliohippus**, which evolved from Merychippus. Pliohippus is considered a direct predecessor to the modern horse.

5. **Modern Horse**:
- Finally, the modern horse belongs to the genus **Equus**, which is the current representative of the horse family.

### Correct Sequence:
The correct evolutionary sequence of the horse is:
- Eohippus (b)
- Mesohippus (a)
- Merychippus (d)
- Pliohippus (e)
- Equus (c)

Thus, the correct order is: **Eohippus (b) → Mesohippus (a) → Merychippus (d) → Pliohippus (e) → Equus (c)**.