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.