In a recent study published in Science Advances, geologists have presented new evidence supporting the classification of Gondwana—an ancient landmass that existed over 500 million years ago—as a “supercontinent.” This reassessment could shed light on the environmental conditions that contributed to the Cambrian explosion, a critical period marked by a rapid diversification of animal life.

Gondwana, first identified in the late 19th century by Austrian geologist Eduard Suess, was recognized due to the presence of identical fossilized ferns and rock formations found across present-day India, Africa, South America, Australia, and Antarctica. Suess’s observations laid foundational work for the development of plate tectonics and continental drift theories. Previously, Gondwana’s status as a supercontinent was debated because geological surveys had estimated it to comprise about 64% of the Earth’s landmass, below the 75% threshold typically required for supercontinent classification.

The new study, led by Tao Wang and William Collins at the State Key Laboratory of Deep Earth and Mineral Exploration in China, alongside efforts at Curtin University in Australia, re-examined more than 25,000 granite samples worldwide. Using isotopic analysis of samarium and neodymium, the researchers traced the geological signatures of ancient crustal fragments that had been concealed beneath younger mountain ranges in Asia, Europe, and North America. This approach allowed the team to identify additional crustal components previously not linked to Gondwana.

According to Thomas Gernon, a professor of earth science at the University of Southampton, the incorporation of these newly identified fragments raises Gondwana’s landmass coverage to approximately 80% of the Earth’s surface at the time. These findings, clustered around the known margins of Gondwana, provide stronger evidence supporting its supercontinental status, although some uncertainty remains as the presence of similarly aged rocks does not definitively prove that these landmasses were physically connected.

The timing of Greater Gondwana’s existence, roughly 550 to 500 million years ago, coincides with the Cambrian explosion. Researchers suggest that the assembly and subsequent breakup of such a massive landmass would have induced significant geological and environmental changes. These processes likely affected ocean oxygenation levels, climate patterns, and created extensive shallow continental shelves, which may have fostered conditions favorable to the emergence of complex multicellular organisms with hard shells, limbs, and eyes.

Additionally, volcanic activity during Greater Gondwana’s formation may have contributed to warming a previously frozen supercontinent, further impacting the environment in ways that encouraged biological innovation.

The study’s authors argue that the geological dynamics linked to the formation and dispersal of Greater Gondwana played a crucial role in the emergence of early complex life. Looking far ahead, geological activity continues: in the next 200 million years or more, future tectonic shifts could lead to the reunification of existing continents into a new supercontinent, with significant consequences for life on Earth.