Several specimens of a large predatory dinosaur -- including a nearly complete, exquisitely preserved skull -- were recently recovered on the island of Madagascar. The discovery is announced in this week's issue of the journal Science by a team of researchers funded by the National Science Foundation (NSF) and led by paleontologist/anatomist Scott Sampson of the New York College of Osteopathic Medicine of the New York Institute of Technology.
The 65- to 70-million-year-old fossils, attributed to an animal called Majungatholus atopus (a theropod dinosaur), and dating to the Late Cretaceous period, were unearthed on an international expedition conducted by Science paper co-author David Krause of the State University of New York at Stony Brook.
"The specimens of Majungatholus represent another in a series of remarkable discoveries by this research team," said Christopher Maples, director of NSF's geology and paleontology program, which funded the research. "The Cretaceous period in Madagascar has rapidly become among the most important fossil localities of any age in the world."
Theropod dinosaurs have been known from Madagascar for over a century, but almost solely on the basis of isolated teeth -- hundreds of them, each with tiny serrations indicating the predatory habits of the animal. "Our primary goal was to find the owner of those teeth and, as luck would have it, we hit the paleontological jackpot," explained Sampson. "This extraordinary skull ranks among the best known for any dinosaur."
With a total body length of almost 30 feet, Majungatholus was the top predator of the time on Madagascar, likely feeding on the massive long-necked sauropod dinosaurs also found there.
Majungatholus was originally named for an isolated skull fragment thought to belong to a pachycephalosaur, or dome-headed dinosaur. The new skull, with an equivalent bony bump above the eye sockets, demonstrates that Majungatholus was not a "bone-head" at all, but rather a carnivorous dinosaur, a distant cousin of the infamous Tyrannosaurus rex.
Majungatholus belongs to an enigmatic group of theropods known as abelisaurids, otherwise recovered only from India and South America. In particular, Majungatholus shares numerous specialized features with the horned theropod Carnotaurus in Argentina. The occurrence of such closely related dinosaurs on widely separated landmasses may have implications for plate tectonics, the theory that landmasses shift their relative positions as they move slowly across the face of the earth.
Madagascar was once part of the southern supercontinent Gondwana that fragmented during the heyday of dinosaurs. The known distribution of abelisaurid theropods, as well as that of fossil mammals, is consistent with a recently proposed geophysical hypothesis that Gondwanan landmasses, perhaps exclusive of Africa, retained connections well into the Late Cretaceous, much longer than previously thought. "If so," Sampson added, "dinosaurs and other land animals may have been able to disperse across the vast distances between South America and India-Madagascar via an intervening Antarctica."
-NSF-
NSF is making a transition to a new form of electronic distribution of news materials, Custom News Service, to replace the current "listserve." From the toolbar on NSF's home page, (http://www.nsf.gov), you may sign up to receive electronic versions of NSF materials of your own choosing. Also see NSF news products at: http://www.nsf.gov:80/od/lpa/start.htm, http://www.eurekalert.org/, and http://www.ari.net/newswise
Journal
Science