The Age of Dinosaurs in the Land of Gonds

The fossil record of dinosaurs from India provides a highly significant contribution to understanding the origin and evolution of dinosaurs and their paleobiogeographic significance. As India rifted from Gondwana and drifted northwards during the age of dinosaurs, the mobile episode in Indian geology provides a unique opportunity to study the diversity of dinosaurs in time and space. The dinosaurs from the Gondwana and post-Gondwana sediments of India have been collected and studied since their discovery in the 1920s, but the full range of their significance and evolutionary history remained fragmentary. After the independence of India, a renaissance arose in the study of dinosaurs at the Indian Statistical Institute (ISI) under the leadership of Pamela Robinson, as more and more dinosaur skeletons were discovered from different localities. This exploration by ISI paleontologists represented a pivotal moment in the history of vertebrate paleontology in India and became a starting point for a remarkable increase in our knowledge of Triassic, Jurassic, and Cretaceous dinosaur faunas. It inspired a new generation of students working under Ashok Sahni’s direction at Panjab University to engage in the Cretaceous research. This paper offers an updated and comprehensive review of the anatomy, systematics, and evolution of Indian dinosaurs within historical, paleobiogeographic, and paleoecologic contexts. The occurrence of Indian dinosaurs is currently restricted to central and southern India, and the record extends across all three Mesozoic periods. It is generally regarded that dinosaurs originated in the Late Triassic Period in Argentina, about 230 million years ago. However, Alwalkeria, a theropod discovered in the Lower Maleri Formation of India, was contemporaneous with the oldest Argentinean dinosaurs. Similarly, Barapasaurus from the Early Jurassic Kota Formation is considered as one of the oldest, gigantic sauropod dinosaurs with a quadrupedal pose. The Late Triassic and Early Jurassic dinosaurs of India are diverse and document their early radiation. With the breakup of Gondwana, India began to disintegrate and drifted northwards, carrying its dinosaur fauna like a passenger ship, until it collided with the Oman-Kohistan-Ladakh Arc in the Late Cretaceous, forming a biotic corridor to Africa and Europe. The Late Cretaceous dinosaurs from the Lameta Formation, consisting of several species of titanosaurs and abelisaurs, provide intimate documentation of the last ‘geologic minutes’ before their extinction. Along with dinosaur bones, the largest titanosaurid hatchery is known from the Lameta Formation, extending for more than 1,000 km. Most egg clutches contain about 10 to 12 spherical eggs ranging in diameter from 15 to 20 cm. Surprisingly, these eggs were empty, showing no signs of embryos, perhaps indicating hatching failure during some environmental crisis. At the Cretaceous-Paleogene boundary, India was ground zero for two catastrophic events—the Shiva impact and Deccan volcanism—both linked to dinosaur extinction. The combination of twin asteroid impacts (Chicxulub and Shiva), with prolonged Deccan volcanism created an unprecedented and ultimately catastrophic environmental crisis across the globe, triggering the end-Cretaceous mass extinction.