Scientists have identified submerged remnants of a giant lost landmass, confirming that the ancient Southern Hemisphere realm known as Gondwana actually accounted for roughly 80 percent of Earth’s landmass between 550 and 500 million years ago. The findings, published in a study in Science Advances, resolve a long-running debate over whether the ancient landmass met the threshold required to be classified as a true supercontinent.
Unlocking the True Size of Greater Gondwana
For years, Gondwana’s status remained contentious among geologists. Traditional measurements placed the landmass at approximately 64 percent of continental land, falling short of the arbitrary 75 percent value generally considered necessary to attain supercontinent status. Previous estimates indicated the ancient continent made up 19 percent of the total Earth surface. However, a team of researchers led by Tao Wang, a professor of geoscience at the Chinese Academy of Geological Sciences, utilized a global-scale analysis of deep-Earth composition to piece together the scattered fragments.
Tracking Deep Crustal Fingerprints Globally
To reconstruct the past contours of the landmass, researchers gathered over 25,000 rocks from ancient continental fragments. By analyzing isotopes of the elements samarium and neodymium—described by Curtin University geosciences professor and study author William Collins as chemical “fingerprints”—the team mapped out ancient crustal blocks embedded inside much younger rocks.
This global analysis revealed that disparate chunks of Gondwana had been broken apart and strewn across the planet by eons of tectonic activity. The team uncovered deeply buried fragments extending from India and southeast Asia through most of China into Kazakhstan, as well as in central Europe and southeastern North America. Although some Himalayan granites formed as recently as 20 million years ago while others formed at 50 or 120 million years, the analysis proved they were all derived from a common continental block formed approximately 700 to 550 million years ago.
While scientists have long known that the ancient landmass included present-day South America, Africa, Arabia, Madagascar, India, Australia, and Antarctica, this expanded geographical footprint pushes Gondwana’s continental landmass up to roughly 80 percent. According to the researchers, this robust evidence fully qualifies the landmass as Greater Gondwana.
Supercontinent Cycles and the Cambrian Explosion
The confirmation that Gondwana was a true supercontinent provides a missing link for understanding global dynamics, including the dramatic biological changes during the Cambrian explosion. Before about 580 million years ago, most organisms on Earth were simple microbial organisms composed of individual cells. Over the following tens of millions of years, the rate of evolution accelerated rapidly.
This rapid proliferation of complex life, which began about 538 to 541 million years ago, established a fundamental link between deep-Earth processes and the most profound expansion of life in Earth history. Almost all major animal families first emerged during this period, setting the stage for modern species diversity before ending with the Cambrian-Ordovician extinction event approximately 488 million years ago.
Previously, Gondwana was considered too small to create the types of global cycles required to drive such evolutionary shifts. However, the geological upheaval produced by a subduction girdle
of tectonic activity—stretching across 79 percent of Earth’s circumference and shaping the massive supercontinent—supercharged volcanic activity. This activity belched greenhouse gases into the atmosphere and warmed the planet from its previous “Snowball Earth” phase. According to the research team, the combination of this warmer climate alongside an enrichment in new ingredients for life paved the way for the explosion of complex life on Earth.
