U-M researcher co-discovers horned dinosaur in India
ANN ARBOR, Mich.—A team that includes a University of Michigan paleontologist has identified from bones collected in India a stocky, carnivorous dinosaur with an unusual head crest.
The dinosaur belongs to a lineage of predatory dinosaurs known from the southern continents, and the discovery represents the first skull ever assembled of a dinosaur of any kind from India.
University of Michigan paleontologist Jeff Wilson co-led the team with Paul Sereno of the University of Chicago, Suresh Srivastava of the Geological Survey of India and Ashok Sahni of Panjab University. The research was funded by the National Geographic Society and the American Institute of Indian Studies.
“It’s fabulous to be able to see this dinosaur, which lived as the age of dinosaurs came to a close,” said Sereno, a National Geographic Explorer-in-Residence. “It was a significant predator that was related to species on continental Africa, Madagascar and South America.”
The team has named the newly identified animal Rajasaurus narmadensis, which means “regal dinosaur from the Narmada.” (The bones were found near the Narmada River in western India.) The new species will be described in the Contributions of the Museum of Paleontology of the University of Michigan (August 2003). The team will donate casts of the dinosaur’s skull to Panjab University and the Geological Survey of India.
Wilson said the 30-foot-long dinosaur was heavy and strong and would have pursued a diet that included the long-necked sauropod dinosaurs that roamed the Narmada region. It had a distinctive look. “There is a bone that protruded from the top of its head, so we think it had some kind of horn on top,” Wilson said. “Its closest relatives had either one horn or two.”
Dinosaur skeletons are rare in India, in part because the terrain renders many of the key geological formations inaccessible to digging. Scant traces of the new species had been gathered in India over the past century, Sereno said, but no reconstruction was possible. Then, in 1983, Sahni and Srivastava led a major expedition to the Narmada region, collecting hundreds of bones. Working with the Indian paleontologists in 2001, Sereno and Wilson decided to take a look at the 65-million-year-old bones, which had been stored at a regional geological survey office in Jaipur, India. The team members found bones of both meat-eating dinosaurs (theropods) and plant-eating dinosaurs (sauropods), but focused on the meat-eater when they found the center part of a skull. “Then we found the left hip, then a right, then a sacrum,” Sereno said.
A detailed map drawn by Srivastra in 1983 had documented the position of each fossil bone as it lay in the field. “So we got a marker and started coloring in each bone on the map,” Sereno said. The 65-million-year-old bones turned into a dinosaur before paleontologists’ eyes. “As we sat there all dirty on the floor, we suddenly realized that a partial skeleton of a meat-eater had been discovered. We could see one individual dinosaur.” That’s important, said Wilson, because although many dinosaur bones have been found in rocks dating to the Cretaceous Period (65 million years ago) in India, there are few examples of multiple bones belonging to the same animal.
Rajasaurus lived in India before the Himalayas existed, said Wilson. “At the beginning of the dinosaur era, the Indian subcontinent was nested among southern continents, particularly southern Africa, Madagascar, Antarctica and Australia. Toward the end of the dinosaur era, as the continents began to rift and attain a configuration closer to their current positions, India began to drift northward, eventually colliding with Asia to produce the Himalayas.” The discovery of Rajasaurus will help scientists understand what happened to India during the subcontinent’s long northward journey – whether it drifted as an island or maintained connections to neighboring landmasses, for example.
“Rajasaurus is a horned theropod that finds its closest relatives on Madagascar and South America and more distant relatives on Africa,” said Wilson. “This may suggest that India maintained a connection to Madagascar and South America late in the dinosaur era.”
Related links:
University of Michigan Museum of Paleontology
American Institute of Indian Studies
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