| Answer | Crossword Clue |
|---|---|
| MIOCENE | When mammals appeared |
| EOCENE | Epoch when mammals appeared |
| EOCENE | Epoch when modern mammals appeared |
| TRIASSIC | Period when mammals first appeared |
| JURASSIC | Period when birds and mammals appeared |
| TRIASSIC | Period when dinosaurs appeared |
| PALEOZOICERA | When reptiles first appeared |
| EOCENE | Epoch when horses appeared |
| EOCENE | Epoch when monkeys first appeared |
| MIOCENE | Geological epoch when mastodons appeared |
| EOCENE | Epoch when bats first appeared |
| EOCENE | Epoch when horses first appeared |
| ICEAGE | When modern elephants first appeared |
| MESOZOIC | Geologic era when plants and dinosaurs appeared |
