| Answer | Crossword Clue |
|---|---|
| EOCENE | Epoch when monkeys first appeared |
| EOCENE | Epoch when horses first appeared |
| EOCENE | Epoch when bats first appeared |
| EOCENE | Epoch when horses appeared |
| EOCENE | Epoch when mammals appeared |
| EOCENE | Epoch when modern mammals appeared |
| MIOCENE | Geological epoch when mastodons appeared |
