I'm interested in how did emperor penguins survive previous warmer periods on Earth? The last time there was no ice at all in Antarctica was 33 mln years ago. T

I'm interested in how did emperor penguins survive previous warmer periods on Earth? The last time there was no ice at all in Antarctica was 33 mln years ago. That's a very long time in a species evolution, but during these last 33mln years there were many times when the amount of ice in the Antarctica shrunk by a lot. Most recently about 140k years ago. Have emperor penguins not been evolved yet 140k years ago? Have they just barely make it through? (just like humans during the last ice age - various estimates claim around 1k humans ~ 200 females that managed to survive at some point during the last ice age are the ancestors of all humans alive today). For an interesting chart of temperatures in recent geologic record see this link https://iceage.museum.state.il.us/content/when-have-ice-ages-occurred https://iceage.museum.state.il.us/content/when-have-ice-ages...