The ancient supercontinent of Gondwana, as we think of it, came into being about 500 million years ago. We refer to that time as the Ediacaran, the time of the beginnings of multicellular organisms. These were exotic and primitive beasties, interesting segmented worms, rounded jellyfish-like organisms, enigmatic tubular and sea-pen-like beauties.
Gondwana split into the landmasses we know today about 180 million years ago. Not lost, just reformed as Africa, South America, Australia, Antarctica, the Indian subcontinent and the Arabian Peninsula. Gondwana joined with other landmasses to become Pangea by about 300 million years ago, before morphing again into Laurasia. By the middle of the Eocene, some fifty-five million years ago, only Australia, Antarctica and South America remained as they straddled the South Pole.
Free of ice and the giant marine and flying reptiles, a new line-up of mammals, flightless birds, crocodiles, snakes and turtles thrived in the warm, wet climate, rapidly adapting and dominating the forests, oceans and skies. New and fanciful creatures, the monotremes, marsupials and placentals explored and took root in the Gondwanan forests as conifers gave way to broad-leaved trees in an ever changing landscape.