| Similarity | Rank | |
|---|---|---|
| pliocene | 0.883 | 49115 |
| ordovician | 0.883 | 22032 |
| glaciation | 0.878 | 30769 |
| permian | 0.872 | 18568 |
| miocene | 0.867 | 31987 |
| eocene | 0.863 | 39949 |
| post-glacial | 0.860 | 38769 |
| palaeozoic | 0.855 | 17635 |
| triassic | 0.855 | 19513 |
| cretaceous | 0.852 | 15845 |
| mesozoic | 0.848 | 21369 |
| proterozoic | 0.846 | 68404 |
| ice-sheet | 0.844 | 47735 |
| interglacial | 0.844 | 34937 |
| precambrian | 0.842 | 28924 |
| silurian | 0.840 | 24411 |
| devonian | 0.836 | 17422 |
| oligocene | 0.836 | 52381 |
| periglacial | 0.833 | 45595 |
| cenozoic | 0.830 | 76640 |
| refugium | 0.829 | 66085 |
| mid-to | 0.827 | 97597 |
| glaciate | 0.825 | 54958 |
| archaean | 0.823 | 68387 |
| orogeny | 0.822 | 34390 |