A tiny chunk of Australia seeded Southeast Asia's tropical forests 50 million years ago, plant fossils preserved in amber reveal

Southeast Asia's tropical forests owe their rich biodiversity to a tiny fragment of Earth's crust that split from what is now northwestern Australia roughly 150 million years ago, a new study reports.

The fragment transported hundreds of flowering species and a flourishing collection of other ancient plants north across the prehistoric Tethys Ocean, the research reveals. The findings contradict previous theories that the fragment originated closer to what is now Southeast Asia and that Southeast Asia's tropical forests evolved sometime after the extinction of the dinosaurs around 66 million years ago.

At the time the fragment formed, Australia was connected to Antarctica and India within the ancient supercontinent Gondwana, which the Tethys Ocean separated from another ancient supercontinent, called Laurasia.

After drifting northward for 100 million years, the microplate eventually collided with Southeast Asia, seeding tropical forests that evolved into the lush ecosystems found in this part of the world today, the researchers said.

"The rich tro...