Image: BILL PARSONS
From deposits in northwestern Madagascar, paleontologists have unearthed the remains of a strange dinosaur that roamed the region some 65 to 70 million years ago. The researchers describe the novel beast today in the journal Nature.
Scott Sampson of the University of Utah and his colleagues identified the dinosaur on the basis of bones recovered from several individuals, which together represent about 40 percent of the animal's skeleton. The team dubbed their discovery Masiakasaurus knopfleri, deriving the genus name from the Malagasy word "masiaka," meaning vicious. The species name, however, refers to Mark Knopfler, lead singer of the Dire Straits, whose music seemed to bring the researchers good luck: whenever they listened to the band's music in the quarry, they seemed to find more bones of Masiakasaurus.
Masiakasaurus was a featherweight by dinosaur standards at around 80 pounds. But whatever pizzazz the petite specimen lacks in size it makes up for in its peculiar dentition. Indeed, the teeth and jaws of the creature even mystified the paleontologists who discovered it. "When we dug up the first lower jaw bone, we weren't even sure it belonged to a dinosaur," Sampson recalls. "It was only after we compared it with the lower jaws of other carnivorous dinosaurs that we became convinced as to the nature of the owner. Certain features at the back of the jaw are unmistakably theropod." The new dinosaur's dentition is particularly strange because theropods tend to have the same kind of teeth in the front of the mouth as they have in the back of the mouth. Masiakasaurus, in contrast, has flattened and serrated teeth in the back, but conical, slighly curved teeth in the front. The team suggests that the creature probably fed on mammals, snakes, lizards, fish and insects.
Masiakasaurus shares some specialized characteristics with predatory dinosaurs known from India and Argentina, which reveals that a radiation of small-bodied theropods took place during the late Cretaceous period in the Southern hemisphere--much as it happened in the Northern hemisphere. Moreover, the broad geographic distribution of these small dinosaurs and their larger-bodied cousins, the abelisaurids, may support a recently proposed geophysical hypothesis. This model holds that the landmasses that once formed the giant supercontinent Gondwana may have retained connections much longer that previously thought. "If so," Sampson remarks, "dinosaurs and other land animals may have been able to travel the vast distances between South America and India-Madagascar."