100 million years from now; the Earth warms up
The ice age has ended. The ice has melted, and sea levels have risen, changing the shape of the coastlines. The continents are still moving. Australia has collided with Asia, pushing up a huge mountain range. Part of Africa has split off and become fused to the tip of Asia.
Antarctica has been pulled north by a subduction zone at the bottom of the Indian ocean and now lies partially in the tropics. Instead of snow, ice and penguins, there is now dense tropical rainforest. This rainforest has evolved from whatever plant species made it to the isolated continent first. Similarly, the animals there have radiated to fill all the available niches have evolved from relatively few ancestors, as reaching this virgin continent was so difficult.
The lichens and, mosses and algae that lived in the Antarctic in the human era have evolved and developed. Seeds and spores from other parts of the world have been carried to the Antarctic. New species have been developed by adaptive radiation.
Antarctica lies in the tropics, with trade winds bringing warm rain all the year round.
The winds bring seeds and spores from South America. Spiders and insects have been carried there as 'aerial plankton'. Birds follow them, staying for the seeds, fruits and insects.
The forests are temperate and wet.