Before the Quaternary Glaciation, stegosaurs still thrived in the Indian Subcontinent, in The New Dinosaurs: An Alternative Evolution.
During the Paleogene and Neogene a large triangular piece of ancient Gondwana (the Indian Subcontinent), over 3,000 kilometers (1,900 miles) long and 2,500 kilometers (1,550 miles) broad, moved northeastwards across the Tethys ocean and fused with the northern continent of Asia. It threw up the greatest mountain range on Earth, the Himalayas, along the join. The Gondwana animal life, such as the few remaining stegosaurs, continued on this new triangular peninsula with little change, isolated from the northern continent by the Himalayan mountain range.