Fossilized remains of a small and bizarre predatory (or theropod) dinosaur were recently recovered on the island of Madagascar. The discovery was announced today in the journal Nature by a team of researchers led by paleontologist Dr. Scott D. Sampson of the University of Utah. Additional authors on the paper are Dr. Matthew T. Carrano and Dr. Catherine A. Forster, both from the State University of New York at Stony Brook.
These fossils, which date to the Late Cretaceous period (about 65-70 million years ago), represent a dinosaur new to science, dubbed Masiakasaurus knopfleri. Masiakasaurus (pronounced "ma-SHE-ka") was relatively small, as dinosaurs go, with a total body length of 1.6-2.0 meters (5-6 feet), much of which consisted of its long neck and tail. The total mass of this little carnivore would have been approximately 35 kilograms (80 lbs.), roughly that of a German Shepherd dog.
Masiakasaurus is based on a number of isolated bones from several individuals. The great majority of these fossils were recovered from a single site. Included in the collection are parts of the jaws and about 40% of the remainder of the skeleton, with some bones represented by multiple examples.
Without doubt, the most bizarre aspect of this theropod dinosaur is the extremely specialized teeth and jaws. The first tooth of the lower jaw is oriented almost horizontal, projecting forward instead of upward. Subsequent teeth angle increasingly upward until the sixth tooth; from this point backward, all the teeth point straight up. The teeth themselves are also unique. Whereas the teeth at the back of the jaw are typical of theropods-being flattened and serrated-those at the front are longer and almost conical, with hooked tips and only tiny serrations. These features are otherwise unknown among theropod dinosaurs, which tend to have teeth of the same type front and back.
Sampson stated, "When we dug up the first lower jaw bone, we weren't even sure it belonged to a dinosaur! 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 first part of the name of this new dinosaur is derived from masiaka, the Malagasy word for "vicious", and sauros, which is Greek for "lizard". The second, part, knopfleri, honors singer/songwriter Mark Knopfler, lead singer of the musical group Dire Straits.
The reason for the reference to Knopfler is two-pronged. First, to help pass the time excavating fossils under the baking Malagasy sun, expedition crews played and enjoyed a great deal of Knopfler's music. Second, and perhaps more significantly, his music appeared to have an additional, unanticipated effect-it brought good fortune in the hunt for fossils. Whenever Knopfler's music was played in the quarry, crew members seemed to uncover more bones of Masiakasaurus. Although naming a dinosaur after a musician is hardly standard paleontological practice-indeed this is likely a first-the expedition crew thought the decision to be entirely appropriate. As Sampson puts it, "Finding fossils entails a heavy dose of serendipity, and we'll take good luck any way we can get it!
Masiakasaurus shared its island home with at least one other carnivorous dinosaur, Majungatholus atopus. At 7-9 meters in length, Majungatholus was the top predator of the time, likely feeding on the massive long-necked sauropod dinosaurs also found there.
The diet of the smaller cousin, Masiakasaurus, with its unique teeth and jaws, is much less certain. There are a few species of living mammals-including various shrews, as well as a group of South American marsupials known as caenolestids-that may provide an analogue. These mammals possess a similar dental set-up, with elongate, conical, forward-projecting teeth up front. In virtually all cases, the front teeth are used for grasping and piercing rather than tearing and slicing, and the prey generally consist of insects.
The jaws of Masiakasaurus suggest a similar feeding strategy, with the front teeth used to capture and manipulate animal prey, and the blade-like rear teeth then slicing and tearing the victim into bite-sized chunks. As to the nature of the preferred prey of this little dinosaurian carnivore, potential candidates include insects, fish, lizards, snakes, and mammals.
Masiakasaurus and Majungatholus, the two known Malagasy theropods, are members of an enigmatic group known as abelisauroids, and recovered only on southern hemisphere landmasses. In particular, the fossils of Masiakasaurus share a number of specialized characteristics with predatory dinosaurs found in Argentina and India. This finding indicates that a previously unrecognized radiation of small-bodied predatory dinosaurs spread across much of the southern hemisphere toward the end of dinosaur times, paralleling the Late Cretaceous radiations of small-bodied theropods (such as dromaeosaurids and ornithomimids) in the northern hemisphere.
In addition, the broad geographic distribution of these small-bodied theropods parallels that of their larger-bodied cousins, the abelisaurids, a finding that 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, which fragmented during the Mesozoic heyday of dinosaurs. The known geographic distribution of abelisauroid theropods large and small is consistent with a recently proposed geophysical hypothesis that many Gondwanan landmasses 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 travel the vast distances between South America and India-Madagascar because the two regions remained connected via intervening land masses."
Madagascar is the fourth largest island in the world, situated off the southeast coast of Africa. In contrast to the living plants and animals on the island, the great majority of which are highly endemic (that is, known only from Madagascar), the picture emerging from the Late Cretaceous of Madagascar is one of unexpected cosmopolitanism. In other words, the animals preserved in the Late Cretaceous of Madagascar closely resemble those found on other southern hemisphere continents. In addition, it appears that the ancestors of modern Malagasy animals had not yet arrived by the Late Cretaceous, suggesting that they reached Madagascar following its isolation as an island.
Funding for the Madagascar project has been provided by the National Science Foundation and the National Geographic Society, with additional support from The Dinosaur Society and the Field Museum of Natural History, Chicago. In addition to the Masiakasaurus specimens, five years of expeditions have resulted in spectacular finds representing a diverse array of vertebrates including sauropod dinosaurs, mammals, turtles, snakes, crocodiles, and even birds such as Rahonavis, a key link between birds and dinosaurs.
Masiakasaurus and thousands of other fossils from the Late Cretaceous of Madagascar were collected during five expeditions led by Dr. David Krause of the State University of New York at Stony Brook. During their time in Madagascar, one of the poorest countries in the world, the team recognized a critical need for education and health care. Krause and his colleagues have established a non-profit organization, the Madagascar Ankizy Fund ("ankizy" means "children" in the Malagasy language), with a mission to build schools and clinics in remote areas on the island. A two-room schoolhouse has been built in the primary field area where Masiakasaurus was found, and several temporary clinics have been held in various parts of the country. For more information, see http://www.
Public Relations at the Utah Museum of Natural History, University of Utah (please coordinate directly where possible):
Senior Author of Publication
Scott D. Sampson, Ph.D.
Curator of Vertebrate Paleontology, Utah Museum of Natural History
Assistant Professor of Geology & Geophysics, Dept. of Geology and Geophysics
University of Utah
Co-authors of Publication
Matthew T. Carrano, Ph.D.
State University of New York at Stony Brook
Catherine A. Forster, Ph.D.
State University of New York at Stony Brook
For information on the Madagascar Ankizy Fund, contact:
David W. Krause, Ph.D.
State University of New York, Stony Brook
Phone 1: 631-584-9579
Phone 2: 631-444-3117
Other Qualified Scientists Able to Provide Comment on Publication:
Sankar Chatterjee, Ph.D.
Texas Tech University
Phone: (806) 742-1986; Fax: (806) 742- 1136
Rodolfo A. Coria, Ph.D.
Museo Mun. Carmen Funes
Phone: (0943) 63055; Fax: 54-99-63154/64039
Philip J. Currie, Ph.D.
Royal Tyrrell Museum of Palaeontology
Phone: (403) 823-7709; Fax: (403) 823-7131