A new Science Advances paper says Gondwana covered roughly 80% of Earth’s continental landmass, above the 75% threshold often used to define a supercontinent.
The revision comes from identifying a buried Gondwanan block formed about 700–550 million years ago, traced from India and Southeast Asia through much of China into Kazakhstan.
That region had largely been interpreted as former ocean floor and volcanic island chains, but granite isotope data showed the mountain belt sits on older continental crust tied to Gondwana.
The finding strengthens models linking Gondwana’s assembly 750–550 million years ago to a nearly 35,000 km volcanic arc whose long-lived gas emissions may have shifted Earth from icehouse to greenhouse conditions.
Researchers say that climate transition could help explain why the Cambrian explosion of life followed soon after Gondwana formed.