To understand how they separated, it helps to look back about 200 million years to the supercontinent Gondwana. This colossal landmass contained what is today Africa, South America, Antarctica, Australia, the Indian subcontinent, and Madagascar. As tectonic forces began pulling Gondwana apart, it did not shatter all at once. It broke into massive fragments in a sequence of geological separation.
First, the western half of Gondwana (Africa and South America) split away. Later, Antarctica and Australia drifted off. What remained was a conjoined island landmass consisting largely of India, Madagascar, and the Seychelles. For tens of millions of years, this isolated block harbored a shared ecosystem. Paleontologists have discovered strikingly similar fossils in both regions from this period, including related species of large abelisaurid dinosaurs, proving the two landmasses shared a contiguous environment.
The final breakup between India and Madagascar occurred roughly 88 to 90 million years ago during the Late Cretaceous period. Intense volcanic activity from a mantle plume—specifically the Marion hotspot—weakened the crust connecting them. A colossal rift formed, eventually filling with the waters of the young Indian Ocean.
Once free, India's relentless northward journey ended when it violently collided with the Eurasian plate, crumpling the Earth’s crust and thrusting the Himalayas into the sky.
Madagascar, meanwhile, barely moved. It remained anchored near the African coast, where tens of millions of years of profound isolation allowed it to develop a completely unique, heavily forested ecosystem. Today, examining the rock strata on the eastern coast of Madagascar and the western coast of India reveals a perfect geological jigsaw puzzle, a permanent footprint of the era when these two vastly different places were joined together.