| Answer | Crossword Clue |
|---|---|
| EOCENE | Epoch when mammals appeared |
| EOCENE | Epoch when modern mammals appeared |
| EOCENE | Epoch when horses appeared |
| MIOCENE | Geological epoch when mastodons appeared |
| EOCENE | Epoch when bats first appeared |
| EOCENE | Epoch when horses first appeared |
| EOCENE | Epoch when monkeys first appeared |
| EOCENE | Epoch when mammals arose |
| EOCENE | Epoch when mammals evolved |
| EOCENE | Epoch when mammals began |
| EOCENE | Epoch when mammals emerged |
| EOCENE | Epoch when modern mammals arose |
| MIOCENE | When mammals appeared |
| TRIASSIC | Period when mammals first appeared |
| JURASSIC | Period when birds and mammals appeared |
