| We suggest that the shallow epicratonic platform area of the Canadian Shield may have served as a refugium for relatively archaic taxa. |
| Perhaps the lineage survived as refugium species and thus repopulated during the post-Cretaceous recovery. |
| Moreover, resting stages also afford species a temporal refugium from adverse conditions. |
| The authors hypothesized their common origin from an Atlantic refugium after the last glaciation. |
| Sheep in the Alaska refugium evolved into the slender-horned Dall sheep Ovis dalli, those farther south into the heavy-horned Rocky Mountain and desert bighorns Ovis canadensis. |
| The extinct pine species Pinus matthewsii has been described from Pliocene sediments in the Yukon areas of the refugium. |
