Scientists in India have discovered a new dinosaur species that roamed the Narmada valley 65 million years ago.
The creature, whose fossilised bones were scattered along the Narmada River in the western state of Gujarat, has been named Rajasaurus narmadensis, or the regal reptile from Narmada.
The bones had been collected 20 years ago
Palaeontologist and explorer Paul Sereno, from the National Geographic team who made the discovery, said the beast would have been nine metres (30 feet) long, stocky, carnivorous and a stocky animal with an unusual head crest.
Dr Sereno and palaeontologist Jeff Wilson made the discovery after studying a mixed collection of dinosaur bones gathered by Indian scientists 20 years ago.
They realised they had a new species after finding part of a skull with a horn resembling those of dinosaurs found in Madagascar.
Further investigation showed that the pieces had been found next to each other, as if they had been connected.
"There was a eureka! moment when we realized we had a partial skeleton of an undiscovered species," said Dr Sereno, a professor at the University of Chicago and one of National Geographic's "Explorers in Residence".
Dr Wilson, from the University of Michigan, said: "We know that there were carnivorous and herbivorous dinosaurs in India through individual bones, but we really don't know just how they looked because no two bones can be reliably said to belong to one individual.
"Rajasaurus is important because it represents a partial skeleton and preserves many details that clue us into its evolutionary relationships."
National Geographic says the carnivorous Rajasaurus, which lived in the Cretaceous Period at the end of the dinosaur age, preyed on long-necked titanosaur sauropods, herbivorous dinosaurs that also roamed the Narmada region.
The scientists believe the Rajasaurus is related to a family of large carnivorous dinosaurs, most of which had horns, that roamed the Southern Hemisphere land masses of present Madagascar, Africa, and South America.
Dr Sereno said: "People don't realise dinosaurs are the only large-bodied animal that lived, evolved, and died at a time when all continents were united."
The age of the bones mean Rajasaurus was a contemporary of Tyrannosaurus rex and therefore one of the last species to live before the dinosaurs were wiped out.