The bite stuff: an old jaw provides clues to ancient diversity, ecology, and geography

Natural History, May, 2002 by Scott D. Sampson

Larger abelisauroids were also distributed widely across the Southern Hemisphere, on landmasses that once made up the great southern supercontinent of Gondwana, including Madagascar, India, and South America. By the end of the Cretaceous, shifts of the earth's crust had long since begun to break Gondwana into continent-sized masses, which were then carried toward their present geographical positions. But the wide distribution of abelisauroids, both large and small, is consistent with a recently proposed theory that some Gondwanan landmasses retained connections well into the Late Cretaceous, much longer than previously thought. If so, abelisauroids may have traveled across the hemisphere, perhaps employing Antarctica--then virtually free of polar ice--as a land bridge.

So it turned out that our weird jaw had quite a tale to tell, one with global implications. The little prehistoric predator also demonstrates that we have yet to plumb the depths of dinosaur diversity. Undoubtedly, many new and bizarre discoveries still wait to be unearthed, and we look forward to our next trip to Madagascar.

Scott D. Sampson is curator of vertebrate paleontology at the Utah Museum of Natural History and assistant professor of geology and geophysics, University of Utah.